I'm trying to swap parts between my Classics Bee, Classics Cliffjumper and Henkei Bee to make good Classics Bee and CJ, and a custom. But, I need to switch the red forearms from CJ with the gray ones from Bee. Which means, I have to remove the door pieces somehow. Now, I see the pin, but the piece looks fairly glued together. Anyone have any advice how to do this?