Only found this out today. I wanted to replace the hands for soldier story ones and thought I would have to drill out the wrist pegs. I removed the bp wrist pegs today, I took a pair of snips and carefully sniped out the semi circle plastic piece that hilds the gripper hands. To my suprise once the circular piece of plastic came away the forearm slide off, to expose the lower part of the elbow that slips inside the forearm.
I then simply cut off the access plastic that makes up the wrist peg and slipped the forearm back on. (I did have to use a small amount of insolation tape to stop the forearm slipping back off) then simply slipped in the new soldier story hands. I hope others find this useful