Just had mine apart today and put the CGW reduced power trigger return spring, firing pin block spring and firing pin retaining pin in it, and did a little stoning here and there.
I used a piece of tooth pick. Worked like a champ. The pins should just push out/in when everything is properly aligned for them to be inserted.
First time ever for this gun. I got it 5 or 6 years ago, it was pretty nasty in the nooks and crannies.