A system for modifying a slot in a rotor includes a drill, a clamp connected to the drill and configured to engage with an interior surface of the slot, and means for supporting the drill from a stationary platform adjacent to the rotor. A method for modifying a slot in a rotor includes connecting a coupling to a stationary platform adjacent to the rotor, connecting a drill to the coupling, and locating the drill proximate to the slot. The method further includes inserting a clamp into the slot, engaging the clamp with an interior surface of the slot, and operating the drill to create a cavity in the slot.