Hello, I am trying to repair the back section of my son's Cybertron Optimus Prime, the back piece that holds the shoulder hinge broke. I bought a junker at BotCon and thought I would just swap out the broken piece. I am having a tough time taking the back piece off even though I took all the screws out of the back and hips. I figured I should ask the experts here. If anyone has experience with the toy, I would greatly appreciate it!!! (Sorry if I am posting in the wrong forum, I was told some Radicons might be able to come to the rescue).