My battery pack won't come off.

Tried to clean my 5dm2, and my battery pack won't come off. The dial seems
to just keep rotating, not catching I suppose.

Any suggestions, or...send it to Canon??

Maybe a bit of side-force on the battery pack to try to get it to catch? Is it a Canon pack? I wouldn't send it in, consider a local camera shop first.

Yes it's the canon brand. I'll try a little side pressure. And I guess I could try...wolf camera..ha

I think I read somewhere that cooling the camera down will help with this (but be careful about condensation coming back into a warm room)).
There's plenty of threads on this forum about this issue (I'm just too lazy to go search).

I'm assuming you're talking about the battery grip. I've read in these forums that sometimes the thumbwheel and screw become detached from each other. You may have to send the camera and grip in to Canon, especially if either is still in warranty.

It's a shame the two parts are not bonded together better.

What one member had to do to get the grip off

I pray that you won't have to do this.