Did my badges too, it gives the truck a fresh look.
I used fishing line and a sawing motion behind the badge to get through as much of it as possible until I reached the alignment pins. Enough of the badge was loose enough to pull off the rest of the way by hand. Then comes the time consuming task of removing all of the adhesive from the original badge. I used Goo Gone and VERY CAREFULLY used a box cutter with a razor blade. If you're surgical enough with your technique, you won't eff up your paint.
The new badges just stick right on. I had an issue with one of the badges though. When I did a dry fit, the badge wasn't going to be level, like maybe there was a manufacturing error and the alignment pin was a bit off. I ended up just breaking the alignment pins off flush and stuck in on free-hand.