im not sure what you're talking about from your description. What plastic wheel???
If it broke the lense on the outside, you need a new lense.
If you broke the chrome reflector bucket. You need a new bezel that contains the blinker part as well.
If you somehow broke the little tabs that hold the bulb on the plastic housing. Put a tiny bit of silicone in the bulb and put it on. Let it dry and it'll stay on. Next time you have to change that bulb though you'll have to do some careful pulling/cleaning to take off old silicone and put on new one.
If you broke the socket that the bulb plugs in, go to a parts store and buy a new socket.