Will depend on the make of derringer. They are not all the same. Would suggest you find a gunsmith to do this one. It is cheaper than taking one to them AFTER you work on it.
Take it to a gunsmith. Remove cylinder - remove firing pin pin located under rear site - use finishing nail/small center punch ,place against back of firing pin and tap lightly driving pin toward "removed" cylinder
To remove the firing pin from a Winchester Model 100, first ensure the firearm is unloaded and safe to handle. Disassemble the rifle by removing the stock and bolt assembly. Once the bolt is accessible, locate the firing pin retaining pin or screw, remove it, and gently slide out the firing pin from the bolt assembly. Reassemble the rifle by reversing the disassembly steps.
To remove the firing pin from a Savage 440A shotgun, first ensure the firearm is unloaded and safe to handle. Remove the stock by unscrewing any screws that hold it in place, and then take off the trigger assembly. Next, locate the firing pin assembly, which is usually secured by a retaining pin or screw; remove this fastener, and then gently pull the firing pin out from the bolt assembly. Always refer to the manufacturer's instructions or a gunsmith for detailed guidance if uncertain.
You need a gunsmith
Best left to a gunsmith
Get help from a gunsmith
Best left to a gunmsith.
Find a good gunsmith or machinist
google it.
To remove the firing pin from a Western Field M550 ABD shotgun, first ensure the firearm is unloaded and safe. Disassemble the shotgun by removing the forend and barrel, then locate the firing pin assembly, which is typically housed in the bolt. Carefully remove any retaining pins or screws securing the firing pin in place, and gently pull it out of the bolt assembly. Always consult the manufacturer’s manual for specific instructions and safety precautions when working on firearms.
Remove the firing pin from the rear and the locking bolt will side out the side of the bolt
A firing pin that is mounted on/in a hammer