Slowly separate the halves of the housing and note where the wires are routed while separating the halves.The housing is loosened with 4 screws (PH); dust and vacuum off everything, The CB70 brushes are simply snapped off and replacement is reverse of that. Spray oil on the bearings if you want.Then reassemble the housing being attentive to placing wires where they belong, and then the four screws. Done.
The PAD; this model requires an allen wrench to remove the one (1) center machine screw. Then pry off the pad. It is an interference fit. I wedged a screwdriver between the pad and sander body and tapped the screwdriver\'s end with a hammer all around the pad to do this. Be patient. Dust off everything. Then using a small block of scrap wood on the face of the pad, tap-hammer the new pad onto the shaft and install the machine screw. The pad will self level when tapped onto the shaft and the wood block will protect the hook surface.