Been a long time since I disassembled a Model 12. Friend brought me one to replace safety with big head. Does the whole trigger assembly have to be disassembled to change out safety? If not does it even have to be removed from the stock?

It's been a few years since I took apart a M12 also, but - IIRC - you DO have to remove and basically disassemble the trigger group in order to replace the safety... Others??

I don't think so but it has also been a long time. If I remember you can hold the trigger back, put a drift punch in the safety hole to rotate the safety 90 degrees o get the plunger out of the detent and just push it out. Keep a thumb over the plunger and spring.