A method for repairing a rotor of a turbine includes providing a rotor having a groove portion defined by a circumferential portion of the rotor. The circumferential portion of the rotor is removed to create an opening to provide access to the groove such that the opening, immediately adjacent the groove, is narrower than the groove. A guide block may be extended into a receiving slot separating a first protruding surface from a second protruding surface of the rotor such that a weld area slot of the guide block extends over at least a portion of the opening. The opening may be welded adjacent the guide block to close at least a portion of the opening.