An apparatus is provided for mounting to a support for modifying an ankle-foot orthosis. The apparatus comprises a tooling device having a plurality of holes spaced over an outer surface of the tooling device. The tooling device includes a first portion having a longitudinal axis, and a second portion integral with the first portion and having a longitudinal axis substantially perpendicular to the longitudinal axis of the first portion. The second portion of the tooling device defines an opening for receiving the support. A peg is configured to be inserted into one of more holes of the tooling device. The peg comprises a body portion and a post depending from the body portion and configured to be received in the holes in the outer surface of the tooling device. In one embodiment, the body portion of the peg has a convex outer surface.