I use a hex head bolt. I put the bolt head in the top of the fork and double nut the threaded end with a washer in between the two nuts so it won't drop down into the fork. Have used this homemade tool a few times to take the forks apart.
This is Genius!! and so simple...
I'm going to put this idea way up there with
Gedeon's bolt and cable method for replacing
the center stand springs.
Well Done and thank you for sharing.