How to remove trunk floor at the Junkyard?

Ok so on my 66 dart, the trunk floor is pretty badly rusted out, several areas you see straight to the road. Also the spare area bad. So I think the entire trunk floor needs to be replaced. I found a dart at the junkyard that has a good clean trunk. Now how in the heck do you remove it with manual tools at the junkyard? I have some battery tools, like sawzall, but no way in hell is battery going to get me through that trunk.
I have a good 4in angle grinder, but again, it is plug in. There is no place to plug in tools at junkyard.
What do you guys do? And how do I remove the trunk floor?
Do Pick A Parts junkyards let you bring in generators? (which I dont have but could rent?)