The spar inspection and repair procedure does not have to be performed by a mechanic holding an inspection authorization, as any appropriately certificated mechanic may perform this function.
Since the airworthiness directive doesn't call out a specific repair, the mechanic is forced to either:
- Replace the wing with a servicable unit (likely)
- Replace the wing with a new unit (unlikely)
- Hire the services of a designated engineering representative to evaluate the inspection results and develop a repair procedure, this can be very expensive, and will most likely require the existing wing to be removed to enact the repairs anyway. The IA will have to approve these repairs as they will be classified as major repairs.