I like Stanton's idea on this. I've been down this road before. You have to disconnect the z-bar clutch rod & the boot will slip over the end of the release fork & you can "sort of" get the boot in place.

Re-connecting the clutch rod & have someone YOU TRUST push the pedal in might give you the extra clearance to get the boot all the way installed. WATCH YOUR FINGERS since if your buddy lets his foot off the clutch they might be in a bad spot. Maybe you can figure out a way to jam the clutch pedal down...2x4?

Anyway, do not pull out the clutch fork. I tried that once and had to drop the transmission to get it back in. A real pain in the butt.