Go here. https://forums.iboats.com/threads/how-tos-and-other-great-information.283508/
Read links 14, 15, 17, 18, 2, 3, 4a, and 4b
Start by pulling motor/drive, pull interior, pull cap, cut out bad, remake transom stringers and deck
You don't need epoxy, if done right, poly will last another...