This is fun. I just took the Judy Silver (inexpensive trail fork, air spring and chrome steel stanchions) off my hard tail and replaced it with a clapped-out DVO Diamond (premium heavy duty trail / enduro fork with cartridge damper and a air positive / coil negative spring).
The Judy tops out my little kitchen scale at 2300 grams. The Diamond rings up 2218. It might be a little unfair; the Diamond's steerer is about half an inch shorter
The swap required 2, 4, 5, and 6mm Allen wrenches. 2 for the brake hose guide, 4 for the stem pinch bolts, 5 for the top cap and caliper, 6 for the axle. That's it. Oh, and a screwdriver for the crown race.