The round knob on the side of the bolt, that acts as a bolt guide in the receiver, has to be removed. It holds the rear half of the bolt onto the striker that is held in place by the striker nut of which you asked about making a tool.
The bolt guide tip will most likely be polished and very difficult to see on the opposite side of the bolt. It's there, you just may have to look very hard to see it. I believe a 1/16 inch or 1/8 inch punch will do it.