I was out changing my diff oil on my 14bff and the thing is kinda rusty. I went to pull the filler plug and it really didn't want to turn. So I sprayed some penetrating oil on it, and like an idiot, hit it with the impact wrench with a 3/8" adapter. This rounded it out in short order. It doesn't look like a 3/8" socket extension will ever get a grip on it again. Can anyone give me some suggestions on what to do? Is there some other tool that will get a better grip on this thing? Can I apply heat to it without melting seals or something? Is drilling it out an option without ruining something on the other side or getting metal shards someplace where they can't be flushed out (I sure can't see the hole looking from the inside)? Or should I just buy a diff cover with a filler in it and forget about it? Thanks for any help.