How would i make a gamepass that would change your avatar?

I'm making a game where there's a gamepass that changes your avatar. The way I want it is that it should be optional, and you can reset to change back. But in my game, there's a script that sets your character to the youtuber, "mrflimflam", and I need the script to overide it. I would like an awnser quick, so people don't buy the gamepass, and get angry they didn't get anything.