Abstract: A method and a device for reworking or re-machining the surface and, in particular, the slide tracks of a slip ring while the slip ring is in a built-in state in an appliance or machine using the slip ring. The slip ring is rotated by means of a drive provided in the appliance for rotating the slip ring during normal operation, or by means of an auxiliary drive, while a surface-removing cutting tool or surface deforming tool held in a tool holder or carrier adapted to be attached to the appliance or machine is applied to the surface of the moving slip ring to re-machine or recondition the surface. The invention avoids the necessity of dismantling the appliance or machine for the purpose of removing the slip ring for repairs.