Thanks for the complement
I put the hammer on a block with a relief hole below the sear pin location and knocked it out with a nice straight, flat-ended pin punch. I forget what size it was - it was almost pin diameter, but not quite. I used a 12 oz ball peen hammer choked up so the hammer weight did the work, not a hard swing from an errant arm. The pin came out with two taps very nicely.
The hard part was putting the pin back while trying to keep the new sear's pin hole aligned with the hammer pin hole while the sear spring underneath was making the sear move all over the place, and at the same time start the tiny pin.
I finally assembled the group by using the punch partly through the hammer pin hole and partly in the sear pin hole, held the punch in a vise with the hammer lying flat on top of the vice, then held the pin with needle nose pliers and tapped the pin enough to start it, then removed the punch and drove the sear pin flush with the hammer. I put some masking tape on top of the vise so I didn't mar the hammer case colors.
Once assembled, I measured the let out - it was OK as is, then put the hammer in the gun, checked the double action sear to trigger clearance and stoned the sear face (it needed hardly any) to get the clearance in the Kuhnhausen book, and lightly polished the trigger roundover where the double action sear contacts and glides over the trigger.
STAY AWAY from the single action trigger sear just below the roundover.
Everything I've read said that is sacred and messing with it without a jig is a quick way to a trigger for the scrap barrel.
The book is down in my shop at the moment, but IIRC, the clearance spec was 0.010" - 0.020" with a small chamfer on the point of the double action sear. If you need that number confirmed, wait and I'll look it up and edit this post tomorrow.