Depends to a degree on the aircraft type: Cessna have a fairly comprehensive SRM (Service Repair Manual) as do other types. If there isn't a scheme available engineering may have to rely on the American standard AC43-13.
That in turn is affected by whether the aircraft in question is a Annex 2 or EASA maintained type and the maintenance organisation has authority to carry out complex tasks. Sometimes it's just easier to fit new component and that depends on whether one is available and at what cost.
Ho Hum!