A lock re-pinning assembly including two or more housings and a mounting block. Each housing is configured for use with a corresponding one of a plurality of lock cylinder shells. Each of the housings includes a cylindrical chamber and a channel. The chamber is configured to receive the body of the corresponding shell, and the channel is configured to receive the tower of the corresponding shell. The mounting block includes a mounting block having two or more sections. Each section is configured for use with a corresponding one of a plurality of lock cylinder plugs. Each section includes a cavity configured to receive an end of at least one of the housings, and a cylindrical follower bar having a diameter substantially equal to a diameter of the corresponding plug. Each of the housings is releasably engageable with the mounting block at each of the plurality of sections.