Can you remove the firing pin retaining cotter pin?
Yep. got the cotter pin and firing pin out no prob.
The cam pin rotates but the bolt will not rotate or move back.
BTW, when you say misfired. what happened? Nothing, or whas it an out of battery firing?
I think what happened is the bolt never fully seated because the bolt never rotated into position in the bolt carrier so the cartridge never fired. I ejected the unfired cartridge.
Should I try beating on the bolt with a rubber mallet?