Abstract: A drill assembly comprises a motor guide tube, an adaptor extending from a distal end of the motor guide tube, an elongate drill guide tube extending from a distal end of the adaptor, a retractable guide tube including an arcuate distal end slideably disposed within a channel of the drill guide tube, an actuation lever operably coupled to the retractable guide tube and extending from an outer surface of the adaptor, a flexible drill cable slideably disposed within the retractable guide tube, a drill motor operably coupled to the flexible drill cable, and a push-pull cable extending between the drill motor at a distal end and a liner stage motor inside a control box at a proximal end. A distal end of the flexible drill cable is structured to be advanced through the arcuate distal end of the retractable guide tube, and the linear stage motor is operable to advance and retract the push-pull cable and the drill motor.