A template for use with an instrument to drill a hole in a surface at a desired location. The template includes a body which has a negative impression of the surface, and a guideway having a first end positioned to open onto the desired location when the body is placed in conforming contact with the surface and a second end positioned on an exterior surface of the body. The second end of the guideway is connected to the first end by a passage. The guideway is preferably positioned in a portion of the template which is removable from the remainder thereof. The template also includes a stop for limiting the depth of penetration of the drill bit into the hole, a first fastener for attaching the stop to the body and a second fastener for fastening the removable portion of the template to the remainder of the template.