The first thing I would do is to take a pair of pliers and rip of all the pricks. Put them in a pile that that would take forever to do I am telling you. Then I would start to climb the cactus and as I got my way up the cactus I would take a picture and tell my friends. That I was climbing a cactus without poking myself with the pricks on the cactus. That is how I would climb a cactus.