A system for repairing a defect on at least a portion of an articular surface of a glenoid, said system comprising: at least two guide pins (56, 57), said at least two guide pins (56, 57) comprising a first guide pin and a second guide pin, said first guide pin and said second guide pin configured to be secured to said glenoid; an excision apparatus comprising a first guide body and an excision device; said first guide body comprising a plurality of guide pin sleeves (210, 212, 214, 216) to contain said at least two guide pins (56, 57), said plurality of guide pin sleeves (210, 212, 214, 216) comprising at least a first guide pin sleeve and a second guide pin sleeve, the first guide pin sleeve and the second guide pin sleeve being parallel to each other; and wherein, when said first guide pin is contained in said first guide pin sleeve and said second guide pin is contained in said second guide pin sleeve, said first guide body is retained in a first excision position for said excision device; characterized in that said first guide body further comprises a third guide pin sleeve; and wherein, when said first guide pin is contained in said first guide pin sleeve and said second guide pin is contained in said third guide pin sleeve, said first guide body is retained in a second excision position for said excision device and wherein said third guide pin sleeve is parallel to said first guide pin sleeve and to said second guide pin sleeve, and wherein the center-to-center distance between the center longitudinal axis of the first guide pin sleeve and the center longitudinal axis of the second guide pin sleeve is equal to the center-to-center distance between the center longitudinal axis of the first guide pin sleeve and the center longitudinal axis of the third guide pin sleeve. at least two guide pins (56, 57), said at least two guide pins (56, 57) comprising a first guide pin and a second guide pin, said first guide pin and said second guide pin configured to be secured to said glenoid; an excision apparatus comprising a first guide body and an excision device; said first guide body comprising a plurality of guide pin sleeves (210, 212, 214, 216) to contain said at least two guide pins (56, 57), said plurality of guide pin sleeves (210, 212, 214, 216) comprising at least a first guide pin sleeve and a second guide pin sleeve, the first guide pin sleeve and the second guide pin sleeve being parallel to each other; and wherein, when said first guide pin is contained in said first guide pin sleeve and said second guide pin is contained in said second guide pin sleeve, said first guide body is retained in a first excision position for said excision device; characterized in that said first guide body further comprises a third guide pin sleeve; and wherein, when said first guide pin is contained in said first guide pin sleeve and said second guide pin is contained in said third guide pin sleeve, said first guide body is retained in a second excision position for said excision device and wherein said third guide pin sleeve is parallel to said first guide pin sleeve and to said second guide pin sleeve, and wherein the center-to-center distance between the center longitudinal axis of the first guide pin sleeve and the center longitudinal axis of the second guide pin sleeve is equal to the center-to-center distance between the center longitudinal axis of the first guide pin sleeve and the center longitudinal axis of the third guide pin sleeve.