The following instructions are for solidbody guitars having 25-1/2" (Fender) scale length. For Stratocasters® and clones having standard tremolos and rear-routed spring cavities, the supplied templates should be aligned and used as described, although the routing will consist mainly of trimming.
The guitar top template has three countersunk screw holes. Two of these are equidistant from a laser-etched line that corresponds to the centerline of the guitar neck and body. These are for the mounting screws (the third hole will not be used; it was needed for manufacturing the template). Place this template on a flat surface, countersunk side down, and draw or scribe a line that bisects the two mounting holes (see diagram). This line will be at a right angle to the centerline.
Align the template on the centerline of the guitar top, countersunk side upward. Locate it so your scribed line is 25" from the front side of the string nut (the side facing the fingerboard).
Using a pencil or an awl, transfer the positions of the two template mounting holes to the guitar top. (The single third hole should be ignored; it was used in the manufacture of the template.) With a pen or scribe, trace the template's inside contour onto the guitar. Drill the two mounting holes for screws (we suggest #5 or #6 flathead sheet metal screws, 3/4" to 1" long). These holes must be accurately located and drilled perpendicular to the guitar top, since they will later be enlarged to hold the tremolo anchor screws.
Measure 1/4" from each edge of the top right hand corner of the inside of the template, and mark this location with a centerpunch. Using a drill press and a brad point bit for accuracy, drill a 1/2"-diameter hole here, completely through the guitar body. This hole will serve as a locating index to align the position of the rear template.
Screw the top template onto the guitar body. Using a 1/2" router bit with guide bearing, rout the guitar body inside the template to a depth of 1-1/8", in approximately 1/4" depth increments. The final depths can be routed with the template removed from the guitar; adjust the cutter bit so that its guide bearing will follow the cavity walls.
Place the back cavity template on the back of the guitar, countersunk side upward. Locate the corner of the template over the pre-drilled index hole, as diagrammed. Square up the rear template along the guitar's centerline. Drill mounting screw pilot holes or use double-stick tape to attach the template.
Rout the guitar body inside the template to a depth of 3/4". The rear cavity will meet the front cavity. At this point, the "spring cavity" portion of the template is complete. Continue routing the "block cavity" portion to a depth of 1-9/16". The rear template can now be removed.
Center the tremolo spring mounting claw against the front wall of the rear cavity (the wall closest to the guitar neck). Position the mounting claw on the wall so that its mounting screw holes are 7/16" from the back surface of the guitar. Drill 1/8" diameter holes for the mounting screws. A long extension bit will work best for this. Install the spring mounting claw.
Return to the front of the guitar. Enlarge the previously drilled template mounting holes to accommodate the tremolo anchor screws.
Complete the tremolo installation by attaching the bridge/block assembly and the springs. Solder a control circuit grounding wire to the spring mounting claw, and screw a plastic cover plate over the guitar's rear cavity.