A method of repairing a fuel injector including a plurality of pre-mix tubes that each extend from a fuel plenum to an outlet portion includes removing the outlet portion from at least one pre-mix tube to define an exposed end portion, machining an inner surface of the at least one pre-mix tube at the exposed end portion to form an increased inner diameter relative to an inner diameter of the pre-mix tube upstream from the exposed end portion, and coupling a tube tip to the exposed end portion.