My buddy has western arms (Ithaca) 12 gauge with a busted firing pin that needs replacement and since i have a 20 gauge he ask me how to do, which I don't know how...so I'm asking everyone here!
What the procedure and what pitfalls are to be watched out for, also where can you even get parts for a western?

*Just how do I go about disabling the auto safety on my 20 gauge too?