The worst that could happen is you break it off. Hit it harder (I would anyways)

You'd be moving it CCW so the bolt would/should/could loosen after you break the surface tension.

Last time I messed with one, I left the bolt just a little loose so it pulls out of the way easy, but is still there for support.

I never did get it off. I hit it as hard as I could, but couldn't get much of a swing with the hammer. It'* all back together now. As I stated, I didn't have a reason to take it off other than curiosity to see how dirty it might be, so no big deal. Thanks for all the comments.