While agreeing in principle with gammaray, I found that when the bearings in the motor of ours started to go, the motor itself, was fairly accessible through the light... that is from inside of the room. Once I identified the manufacturer of the light it was a simple matter to get a new motor (they're pretty standard from one manufacturer to the next). The problem with replacing the entire fixture is that the portion above the ceiling is attached to a vent of some sort to take the expelled air out of the house. The housing for the fan apparatus has to be removed, the new one installed and attached to the venting hose. Usually, this can only be done from the attic area and many houses don't have very good access to this. So... if you are reasonably handy, shut the electricity off to the device (I'd suggest at the circuit breaker or fuse box) remove the light and take a look at the fan motor. If it's readily available, remove it and take it to a DIY store. If the attic area is accessible... replace the whole fixture... Good luck!