How to Replace the Rear Hub of Your Mountain Bike
To replace the rear hub on a mountain bike, first you need to remove the wheel from the bike frame. Then, remove the cassette or freewheel from the hub, and take off the end caps, nuts, or bolts that hold the hub onto the axle. Install the new hub onto the axle, tighten the nuts or bolts, and replace the end caps. Install the cassette or freewheel onto the new hub, and then insert the wheel back into the bike frame.