Have you tried to align the firing pin and spring with a punch from the starboard side, start the retaining pin from port and use retaining pin to push out the first punch?
It can be done with regular punches purchased at a local hardware store if you are careful not to mark the hammer of the gun and use wood or plastic to absorb hits.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
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