Not many pics but I'll tell you all the details:
First things first: remove the battery so nothing arcs and you don't get hurt. If you can remove the seat and tank it makes everything really easy, though probably isn't necessary. Save any rubber boots that are on battery lines and reuse them on your new ones.
And some advice. There are three battery lines. Remove one line at a time, make the new one, and replace it. Test to make sure the bike still starts. Move on to the next one. If you remove them all at once you might, say, crosswire the positive and negetive terminals at the starter, fry your solenoid and brand new $100 battery. Ask me how I know
The stock RE wires are crap. This is not specific to the RE, almost all stock moto battery lines are crap. The RE positive lines are 8 gauge (barely adequate really) and they're wrapped in two layers of stiff insulation which makes them look bigger than they are and also makes them a real bear to bend. The negative lead is just a 10 gauge wire. That's really anemic.
Materials:
-10' black 6ga. ultra-flexible battery wire, part #6948K91. It cost me about $25 delivered and was plenty. I could probably make another set from what's left. This is a nice burly wire with very fine conductors and a rubbery flexible insulator. It should be really easy to bend wherever you want/need to and will carry way more current than stock.
-Napa Auto battery terminals, part #784572. These are 6ga. and have a 1/4" hole. $4 at any Napa. I've used these for a long time now. The only time they've failed is from bending back and forth too many times from the battery going in and out too many times.
-Heat shrink tubing. I got some clear stuff at my local Ace Hardware that has a heat activated adhesive on the inside, so it stays put once you shrink it down. $5 for 6", and worth it!
-Electrical solder and a torch.
There are three cables to make.
-Positive battery to starter solenoid.
-Negatve battery to starter motor ground.
-Solenoid to starter positive terminal.
Some REs have a solenoid with the wires permanently attached, covered under some potting compound. If you have one of these you'll need to replace it. Get something like this:
http://www.ebay.com/itm/like/230691411498?lpid=82Get one that's for a 500cc or larger bike. This is what I got as a replacement from CMW when my original died. Throw away the green plastic piece, you won't need it.
The easiest cable is the solenoid to starter positive terminal. This just has two terminal ends with heat shrink. Remove it from the bike. Measure and cut a new line the same length. Remove the rubber boot that covers the starter terminal and slide it to the middle of the new line. Now put the ends on.
Use a razor blade and cut off about 3/8" of the insulation, just enough so that when the wire is inserted in the cable end it comes up just flush with the collar but doesn't stick out. Crip it closed. I used a big pair of Vice Grips for this. Repeat for the other end.
I soldered the ends but just a little bit. Some people will tell you not to do this. If the lin gets hot, the solder can melt out and drip on things. You don't want to use tons of solder. I put just enough solder on the cut end to anchor it to the termninal. If you put on so much that it flows out the other end it will make the line rigid there, it won't flex, and it will break off. Just enouch to fill the top, get it nice and hot with a torch so it flows. Then I tap it off to get rid of all excess. Then heat again to make it flow and make sure it's not a cold solder joint. Repeat for the other end and set aside. Let it cool completely before you put on the heat shrink tubing.
If you can find the adhesive heat shrink, use it. It's pricey, about $5 for 6" but worth every penny. It's really thick and heavy and once heated you can see liquid adhesive flow. It stays put and the thickness helps distribute any bening at the terminal across a wider area so your line is less likely to break off. I cut it long enough to cover the entire metal collar and about 1/2" to 3/4" past that down the line. Hold in place, heat and shrink. Let cool. Now slide the boot back to the end. A little Windex makes this easy.
The other two lines are similar but each also incorporates a small tap line off the main line to feed the electrical system. There is a quick disconnect for these feeds. SAVE IT AND REUSE IT!!!! Do not replace it with a bullet connector. Bullet connectors suck. They corrode and get loose very easily. These quick disconnects are much better, more secure, and much less likely to corrode or fall out and leave you stranded.
Cut the small line as close to the old main cable as possible. Strip about 1/2" - 3/4" of the insulation and wrap it around the stripped section of the new main line. Crimp and solder the end as before. Tug the small line and make sure it's secure. With the heat shrink, make sure it covers at least 1/2" past the metal collar. This is important for these small tap lines since you don't want to be yanking at the line near the terminal. The small line will fatigue and break, leaving the bike dead. The heat shrink distributes the load.
For the negative line I made one the same length as the original. For the positive I made one longer because I'm routing it a different way. On my C5 it was running right along the backbone of the frame. That has some problems. It gives you almost no room to maneuver and get it attached to the battery, or to push it back in place as you insert the battery. I routed it lower, behind the battery bracket. The line is a little smaller than the original (since it doesn't have two crappy layers of insulation) so this was easy. I figure I'll route it up from there to the positive terminal. This gives me an easier angle of approach and more slacke to slide the battery in and out but I'll have to be careful I don't leave too much slack. If there's too much slack it will swing around and either chafe through the insulation or break off at the terminal.
If you're wiring routes don't match mine, done't worry. I'm pretty sure not two REs you run across will have the exact same wire routing. Again, this is not unique to RE, most motos are like this. I'll try to get some pics and add them to the post.
On batteries, I got the MotoBatt AGM for about $100 and was really happy with it. It has threaded holes that you're supposed to bolt these little terminals to, then bolt the wires to the terminals. I tossed the terminals and just bolted the lines to the threaded holes in the battery. Since they are recessed it was really easy to bolt up and get the battery in place. As mentioned above, I fried that battery through my own stupidity. I wasn't really up for another $100 so I looked around and found Chrome Battery for $42 shipped. It's an AGM but with more common terminals. It's the 14L-A2, exact same size as the original. It will probably be a hassle to get in but the terminals are a bit different and that should be easier.
For attaching more leads for chargers, etc. The positive line has always been the the biggest pain for me because of where it is and how little room there is to get anything in there. I plan to bolt my charger line to the solenoid instead. It's the same connection, but I don't have to wrestle with it every time I put the battery in and out. Unfortunately the negative lead doesn't go anywhere so convenient. It's got a bit more room behind the battery, but I may add a 6" long 12 ga. line to the terminal and attach to that. That should be a bit more convenient since I don't have to deal with more than one ring terminal going to the post.
Scott