Welcome to the Cart Tek Service Support Center. The below video will show you how to replace the "clutches" or one way bearings that drive the wheels on your GRX900 or GRX950. You will need a "snap-ring" pliers to perform this task. If you do not own a pair of pliers, they can be found at a local hardware store for under $10.00. During the disassembly process, make note of exact placement of washers. They are of different thicknesses and need to be replaced in the same position. If you have any questions or concerns, please feel free to call us. 541-633-4308