Hi Dan,
Firing pins on the 1919, I think that gun works on an open bolt, thus the firing pin might be fixed to the bolt, removing it would require removing the bolt completely, I'm not an expert but I think that might ruin the display.
On the Garand and carbine it is difficult to remove the firing pin but achievable, you have to remove the bolt by taking the gun apart, the bolt is one of the last things to get out, remove the extractor, and ejector to get to the pin. Send me your Phone number to 952-807-1030 and I can send you a photo and description from the Garand Service Manual and Carbine Manual. Or there is the gunsmith option?