remove the repair and replace - but that's not a big deal on these airframes. In extremis, scrap the affected part.
It's not a big deal for a glider workshop with the correct information about how to repair, though it can take time. I saw an ASH25 wing that had to have a hole cut to fix a problem with one of the rods inside the wing. The hole was about 10cm, but to repair it it was scarfed to about 25cm, and there were a lot of layers in the repair. It was on the underside and the final repair was just about invisible.
Sometimes repairs show in one light and not another, or on a damp day rather than a dry day.
If the extremis is to scrap a part given you are scrapping the fus, a wing or the tailplane, that's scrapped the whole glider.