sand it back to the timber and feather out the edges, you can put "everdure" by international which is a timber preservative then once dry tape up boat exept the repaired damaged and spray 2pac undercoat eg International "interprotect" can be rolled too, then you can go to a paint shop or do it your self colour match the paint and spary it on. its ok if you make a mess as you can once its dry wet n dry the area and polish it to blend in

Matt