Never tried it on a TJ or a YJ, but I did have to do it on an older toyota carolla. I ended up loosening/opening the line at the clutch cylinder on the firewall and having my gf push in the clutch. A couple of cycles of that and it was good to go.
Not sure if that would (or even could) work for you though.
His: 1999 Flame Red TJ, With a few mods...
Hers: 1987 Grand Wagoneer, stock w/Falken Wildpeak ATs