I would probably say from all the broken pickups that I have rewound and restored is because of human error. When you start removing pickups from assemblies and mounting rings there is a greater risk of damaging the pickup. On single coil pickups the majority of pickups have exposed beginning and finish magnet wires and can easily be damaged from mishandling. Removing plastic or metal covers can snag the coils. Removing tape or other coatings from coils can break the fine magnet wires.
Removing the pickups and throwing them in a drawer will only cause them to be damaged and should be carefully wrapped up and put safely in a container and away from little fingers. If your pickup works, either leave it or have an experienced repairman do the necessary modification. Pickups are valuable and the heart of your instrument. Don't take the risk of destroying your pickup and perhaps the unique tone of your instrument.
WRITTEN ON JUNE 12, 2015, BY