Is the firing pin tip protruding through the hole in the breach face?
If so, the bolt is de-cocked and you need to pull back on the sear ledge of the cocking sleeve with a piece of wood or screwdriver to get it to clear the recess in the bolt. This will allow it to turn out counterclockwise.
Edit adding link I found on YouTube. This may help better than I could describe. Not my video, but i wish I would have found this video the first time I had this problem
This is the way I did it on the edge of a block of wood
Hellfire, Doom, Watch the hatred spin
Beyond the speed of sound---
Fire it up, Let the engines roll
It's time to burn it down