A guide tool (100) for guiding resection of a bone piece, comprising a body (102), a burr guide opening (130) extending through the body (102) and defining a burr resection surface, and a saw guide opening (120) extending through the body (102) and defining a saw resection surface, the burr guide opening (130) and the saw guide opening (120) being aligned such that the burr resection surface and the saw resection surface intersect, defining a bone piece resection surface.