Step one was to disassemble, unwire, and clean the guitar inside and out. The pickguard was unshielded (invites hum), so best-quality copper shielding was applied. The pickup supplied for the middle position was a double-coil blade pickup designed to fit in a stratocaster single-coil slot. All three pickups were capable of coil-tapping, so the old controls were replaced with new push-pull types for coil tapping the neck and bridge pickups. The customer wanted a mini- switch installed between them to allow the new middle pickup to be coil-tapped as well. The 3-position switch was replaced with a new 5-position switch which performed the same as a Strat. Finally, an anti-grounding-shock capacitor was placed between the ground and the bridge/strings. Wires were bundled, the guitar set up and tested before a final buffing.
This guitar is an example of some pretty fine cleanup and electronics work. The guitar came with two humbuckers and an empty middle slot in the pickguard. It had a 3-position pickup switch. It was very dirty inside and out and had shoddy wiring (the tone control wasn't even connected) and incomplete shielding.