A system and method for modifying a gas turbine engine in the field to drill a series of cooling holes in a turbine rotor disk made of a superalloy. A portable field repair system includes a stand configured to receive, support, and position a turbine rotor disk, a drill having a self-feeding spindle and configured to automatically drill a predetermined depth through a superalloy and to automatically stop upon completion, a drill guide configured to coordinate the drill with a plurality of radial axes associated with a precise hole pattern to be cut and a drill mount configured to mechanically couple the drill to the drill guide and to position the drill during the modification of the gas turbine engine turbine rotor disk.