They're press fit into the rods. So, you could either pay to have them pressed out, and pressed back in, or you can do it the way I did.

I used a hammer and a socket and drove them out.

I used a propane torch, with a wide flame and heated the rod up, not red, not turning it colors, just make sure its fairly hot.

While I did all this, I left the new wrist pin in the freezer. I put the piston on the bench, with about 1/8" washer to keep the wrist pin from going all the way through. The wrist pin floats in the piston, so you'll want to keep it as centered as possible in the rod.

Mines together, boosted and runs great.