Righto, 410! I'm posting some more photos because I found this hatch modification so enjoyable, and worthwhile, and want to encourage others to go for it. I know there's threads on this mod elsewhere, but this procedure is part of my "lean codes" story and others searching this same problem may be led here and will find this resolution useful.
Everything is ready for the pump's arrival tomorrow. Made a hatch cover (using snips on some same gauge steel from my salvage shelf), drilled screw holes, test fit the cover and formed it around the folds a bit with a hammer. The 5/16" nuts are loosened on the pump lid. Should take 5 minutes to finish. So much easier than emptying and dropping the tank (a sweaty, dangerous and ugly job under the vehicle), and easy access for next time! And, no longer jealous of the wife's Sentra's under seat fuel pump hatch!
Here's some tips:
• park with windows, rear hatch window and back doors open to catch the breeze, move front seats forward.
• unbolt and remove rear seat behind driver, unbolt front legs only for passenger side, hold passenger side seat back with bungie cord (gives you plenty of room)
• use a hammer and center punch holes to make an outline of desired hatch (see photos to determine area)... mine's about 10" wide and goes about 2" up the back slope. Then use a chisel to connect the holes. When done, I hammered the edges to smooth them somewhat. Do not use tools which make sparks (grinders, rotary tools, etc.)!
• once fuel pump assembly lid and top of tank is exposed, blow off entire area with air, removing anything that might fall into open tank
• pull up and disconnect electrical connector that may lie a bit down the driver's side of tank, and tie a cord around female end so you won't be fishing for it later.
• the other connector is a bit back and to the passenger side... a little harder to get to... but use a long regular screwdriver to press the lock tab, then use to pry male from female end.
• ensure pressure in fuel lines has been released... (mine had none, that's how I got involved in the first place!)
• blast fuel line connection with air, then PB Blaster (let it sit a little), then more air
• holding a fuel line tool (get one, they're cheap) in place, rock the female end back and forth with a locking pliers as you pull it off. Don't lock on too tight and crush your fitting.