Fuel Pump Install..Some tips...

Get it up as high as you can get it and put jack stand under the axle. Get as much gas out of ther as possible. You got the rest just about right. When you get t he tank out you'll see the locking ring that holds the pump assembly. Take some compressed air and blow that area off real good There will be a lot of dirt in that area and a lot of it will go into the tank if not blow off. Take your time and remember fuel vapor is dangerous (use a brass or rubber hammer to unlock ring at pump)

i just added a 255 pump 2 days ago. i jacked up the car by the diff as high as i could.
things to get: new fuel filler pipe gasket, it's a little rubber seal for the gas tank filler hose to seal it up. make sure you get a new one the old one won't seal again, i didn't find this out till i had the tank instaled, got gas and basicly dumped about 3 gallons all over the place at the gas station and on the road. i didn't blow up but you may not be so lucky, pusd you gota drop the tank again, so get the gasket!!!)

then take 2 jack stands and place them right where the lower control arm stops, put it on the frame peice about 3 inches forward from where the frame goes up to get over the axles.
go inside the fuel filler door and unscrew the 3 bolts that hold the gas cap and the one above it off. this will le tthe filler tube be able to be removed (it will be a bi*ch don't try and remove it just yet.
ONe thats done take a flat peice of wood or use a flat plate on your jack and pump the jack up till it hits the gass tank. undo the 2 bolts that hold the tank ona little at a time, go back and forth to each one but dont take them out. (there about 1.5inches long) so go out about .5inches or so on both. then grab the filler tube and pull it out as far as you can, it won't come out so don't worry.
take the tank bolts all the way out, and do it slowly to make sure the tank is stable. (2 or more ppl is a great deal of help from now on.) once the tank is stable lower it about 2-3 inches and slide it awya from the fill tube while pulling the fill tube out, just keep going down and away till the fill tube comes out. lower it about 8 inchesyou'll see a wire twords the front right of the tank. you gota pull out the sensor. it pops out so just yank on it gently. then you can lower it even farther. remove the 2 fuel lines from the tank. and unplug the sensor in the middle. there should be no more lines going into the tank then if there are remove them. drop the tank all the way downand pull it out from under the car. you can take it off the jack, put some cardboard down and lay it on that. use a brass punch or block of wood to remove the innner ring on the pump. tae the pump out, you'll have to turn it a bit to get it out also note the orientation of the filter to the position of the tank. the new one has to go in the exact same plce or it won't go down in the tank right. now follow the fuel pump instructions to hook the new one up. just do the reverse then. make sure you ut the new filler tank gasket in now though. place the tank back on the jack and put her in place remember to hook up all of the lines plugs etc... You'll have to leave it liek 4 inches or so down till you get the filler tube started (use wd40 to lube up the pipe and gasket it'll make it much easyer) once it's all done turn the key and listen for the pump, if it works go test her out!

I like to be detailed, let me know how the install went i hope this helps dude