Put 1 bolt back on loosely, 4-5 turns with your hand. Take a Rag and bunch it up so it acts as a cushion and place it on the inside of your rim and hit it a couple times with a large hammer.Originally Posted by Dash01
The bolt is to stop the wheel from flying off ones it comes loose.
Once the wheel is off, clean both the hub surface and the part of the rim that sits on the hub, lubricate when you put it back.