That pin doesn't need to be drilled out. I just did that Model 38 I mentioned about two months ago and that pin drives out from the outside.
If you decide you want to do it yourself:
Find the outline of the pin (it will be very faint), then use a center punch to get it started. Once it starts, then use a regular flat punch to drive it out the rest of the way. It's a very tight press fit, so don't expect it to just slide out.
If you elect to buy the part from Numrich, you will drive the pin back in very carefully so as not to bend the trigger pivot part of it until it seats in the countersunk recess. I used a piece of small tubing the same diameter as the flange. At this point, it will stand proud on the outside and you will need to CAREFULLY file it down to match the contour of the frame and then polish it. If you leave it polished, it will be close to, but not exactly like, the nickel finish.
If you decide you want to do it yourself:
Find the outline of the pin (it will be very faint), then use a center punch to get it started. Once it starts, then use a regular flat punch to drive it out the rest of the way. It's a very tight press fit, so don't expect it to just slide out.
If you elect to buy the part from Numrich, you will drive the pin back in very carefully so as not to bend the trigger pivot part of it until it seats in the countersunk recess. I used a piece of small tubing the same diameter as the flange. At this point, it will stand proud on the outside and you will need to CAREFULLY file it down to match the contour of the frame and then polish it. If you leave it polished, it will be close to, but not exactly like, the nickel finish.