Need Help - Fuel Leak

[76sierraclassic]

Well, I have discovered that I have a somewhat substantial fuel leak back around my gas tank on my 76. I just crawled under the truck and it appears to be one, or possibly both, of the rubber lines that come from the sending unit in the tank somewhere before they hook up to the hard lines running up front.

I'm making the assumption that those hoses need to be replaced, but it doesn't look like that will be an easy task without dropping the gas tank. Is that correct? I can see where the hoses connect to the sending unit by looking between the bed and the cab, but I don't see away to get to them to replace them. If I do have to drop the tank to do this, I need to know how and what to watch out for (other than sparks of course). I've never done that before, and it's probably about 3/4 full or more.

Any tips or suggestions will be greatly appreciated.

Thanks,
Mike