RE: Rustler rear wheel issue
Generally tyres and wheels are sold in pairs, and u can buy pre mounted tyres on wheels.
Most people choose to buy there wheels and tyres sepperat so Thay can mix and match brands ans styles.
U can try to remove the tyre from the rim sometimes u can save the rim. otherwise u will need to buy new rims as well as Tyres
If the wheel is not chrome. Can try boiling the wheel for 10min then ripping of the tyre and finishing with a hobby knife
(the heat helps releasing the glue)
Or
Rip/cut the tyre off then finish it of with a hobby knife