"I don't even think I have enough buckets for all the gas left in it"

My personal recommendation? Cut a hole in the floor of your rig if you have to access the top of the tank. It's a whole lot safer than bucket's of gas sloshing around in the winter when static electricity can arc a spark and send you to glory. Just make sure your saw path doesn't cross over things like other wires and brake lines. As far as the connectors I just cut them off, soldered the wires, shrink wrapped them with the shrink tubing from Radio Shack, then gunked them up with marine grade silicone sealant. Those connectors are for the guys at the factory throwing the tank in as a unit. They're a problem on the road.