I'm removing the 19" Geminis and putting on Uberturbines today, on my non-performance LR Model Y. Does anyone know if I need to do anything special? The mechanic was asking me if they are all the same size, then we noticed they were, but it worries me a bit that maybe I'm missing something. Maybe 2 of them are for the back and 2 are for the front, or does none of this matter and he can just swap them easily? He's going to do it for me in about an hour so I figured I'd ask to see if anyone knows.