Look at the guide pin on the cylindrical hammer portion of the bolt. It is reduced in diameter, and passes through the bolt. Look on the opposite side, you may see the pin. If you drive it out, the hammer will come off the striker rod. Look at the rear of the bolt body. You will see a collar with two cuts for a wrench. Make a little wrench to fit. Unscrew the collar, the striker rod and mainspring will come out of the bolt. Remove the extractor. Lift the hook end, pull foreward. There is a pin underneath that secures the firing pin. Tap it out, it will fall into the bolt. Remove the firing pin.
Look, these bolts are not intended to be dismantled. It can be done, but unless there is a very good reason, don't. The installation of the hammer onto the striker rod is semi permanent. It is easy to break the extractor while trying to remove it.
Better to wash the bolt with solvent, then lube it.
If you can find a new bolt, it will have to be fitted. A used bolt may cause excess headspace.