The hole is more likely due to dry rot than a squirrel. If so, it would probably be best to replace them all anyway. My rig is considerably older, but I had to replace all of mine. I tried to drop my tank. After removing both straps the thing wouldn't budge. And in looking at it, I don't know how it would ever drop down because of the filler neck (which does not appear to be removable). I think the tank was installed before the body.
Anywho, I measured (several times) and cut a hole in the floor. As fate (or skill) would have it, I cut directly above the sender. I was able to replace all of the lines easily. I hated the carpet anyway, so that was an opportunity to replace it with Pergo.