go to HD and get some of that expoxy puddy/clay, I use it on a lot of things, gets hard as a rock and easy to use, just pinch off what little you need, roll it round and bingo put it on...........I fix a leaking gas tank on my international with gas still in it,,,,,,,,,about 7 yrs ago.. still holding
if you can see the bad spot and can get to it, you may not even need to remove it........ the large tube is about 7 bucks.... called ep-400 epoxy putty..always have some around my place