I've not done it on them and dont have one in front of me but if it doesn't come off by removing the cap or if the bottom cup doesn't come off then you probably unscrew the bottom rod end to remove the spring. Just hold the shock shaft with some needle nose.
Exactly the same as every other shock. As slowngreen said, just grab the shaft and unscrew the rod end at the bottom of the shock. The top cap unscrews as well if you need to remove the shaft.
The metal shaft has a hex head located inside the barrel. So, you could stick a 0.05 driver down into the barrel, if you don't want to use pliers on the shaft.