Anyone take apart a Cheyenne grip?

I got a grip that was broken in a trade a while back. It won't rotate to change depth. Anyone know how to take it apart so I don't break it further while attempting to fix it. I have a good working one so I figured it wouldn't hurt to attempt to fix this one. I have tried to lightly force it to turn by getting a good grip on the back stem and trying to free the stuck grip.

to unease the grip, just put some fk irons lube in it and leave overnight. got the tip on this forum before but cant remember who gave the advice. worked great for me on 2 grips

it works or airsof gun oil got that tip from slicksteel great trick to know