Installing a set of Sperzel locking tuners can be a daunting task on some guitars and requires modifications to the headstock that may make someone working on the guitar a little nervous. As long as the tuning post holes match, installation of Sperzel locking tuners on a Fender Stratocaster almost is a matter of swapping the old for the new. However, modification for the Sperzel locking tuners requires drilling some holes in the instrument.
Place the guitar on a padded work surface. Remove the strings. Loosen the sleeve nuts on the old tuning machines with an open-end wrench, then remove the machines and sleeves from the tuning post holes.
Turn the guitar onto its face. Remove a sleeve nut from one of the Sperzel tuners. Insert the nut into the top hole on the headstock. Use the sleeve nut to position the Sperzel installation template. Align the edge guide on the template with the edge of the guitar's headstock.
Hold the template securely in place. Lightly mark the hole for the locking tuner pin on the back of the headstock with an awl or ice pick. Mark pin holes for the five remaining tuners in the same manner.
Check the position of the marks by using a tuner inserted into each tuner pin hole. Correct improper marks, if necessary. Gently increase the size of the marks for drilling with a centre punch and hammer. Check the position of the marks again before drilling.
Place a drill stop on the No. 36 bit to drill holes 5/32 inch deep. Slowly and carefully drill a hole for each tuner pin at the marked locations.
Insert the high E tuner into the top hole in the headstock. Attach the tuner with the sleeve nut and washer. Tighten carefully with an open-end wrench. Install the remaining five tuners in their proper positions. Re-string the guitar following Sperzel's recommended procedure.
Professional installation of Sperzel tuners is recommended for anyone uncomfortable working on valuable instruments or unfamiliar with fine-detail work.