If you're reasonably mechanically inclined, taking apart a hicap isn't too difficult. Do it slowly and place everything on the table in the same spot and try to remember the order in which things were removed. The coiled spring is captive so it won't pop out and fly all over the place.
I was fortunate enough to be given two non functional M16 hicaps by a friend of mine. Never took apart a mag before. I casually took them apart while watching TV, unjammed one and fixed the other, stuck them back together and ended up with two more hicaps for free.
Patience and attention to detail will take you far.