[himalayanC5]

Guys, I was trying to install the bar end rear view mirror but the bar end hex screw is so damn tight that I can't un screw it. Has any don't it before or have any idea on how to do it.

[alladinko]

same same here. used anything i had, didn't move a milimeter

[Bulletman]

It is a difficult screw,  but keep at it and you will get through, you might want to use An impact driver which will solve your problem here is an example.
http://www.grainger.com/product/4LZF7?gclid=CjwKEAjwtYSsBRCDx6rM1v_uqmsSJAAZgf2q9EhA3dO1UxnJFPfkW0lL257FMUR1e37PeRwTGngF4xoCrwvw_wcB&cm_mmc=PPC:GOOGLEPLAC-_-Hand%20Tools-_-Impact%20Sockets%20and%20Bits-_-4LZF7&ef_id=VYIPhQAAAUb7W1yA:20150618002333:s

[no bs]

try the box end of a 14-15mm wrench on the end of your allen wrench and give it a sharp smack. the threads need to be shocked to loosen.be careful using this technique as the box wrench can get out of line with the handle of the allen wrench and could cause foul linguistics to spontaneously erupt.

[suitcasejefferson]

I got mine off by putting Visegrips on L shaped end of the Allen wrench and unscrewing them. I chewed them up a little, but have no plans to put them back, as the bike jut barely fits through the living room door with them off.

[Sectorsteve]

I think i used a punch to move it a bit

[longstrokeclassic]

A quality Hex Bit Socket and breaker bar to loosen, standard Allen key to tighten

[krimp]

A quality Hex Bit Socket and breaker bar to loosen, standard Allen key to tighten

With thread locking compound liberally applied.

[B5 Ben]

 Be Careful removing those bolts, the metal is a little weak and one of mine stripped when I was trying to take it out to install bar ends.

 It was a nightmare, I finally had to get someone to tap the bolt to get it out.

 I replaced the bolts with some better quality ones and its all good now.

 

[pmanaz1973]

I sprayed mine with Kano Kroil and let it sit overnight.  The next morning it came off with next to no drama.  I did use a hammer to provide the impact wrench effect and shock the bolt loose.   The penetrating solvent/oil made a big difference.

[Ducati Scotty]

A few taps and some penetrating oil are good ideas.  Heat would be good too, they are held in with red LocTite or something similar.  This usually gives up with some heat, though it's tough to get it to that bolt and not damage anything around it.