This weekend I finally got my gumption going enough to finish up changing the fuel pump on my MY94 XJ6.
I took some photos of this to show some details that folks who have not done this job might need to see.

Tank pulled out to access the top of the tank

Looking down at the holes under the tank where the hoses attach to the bottom of the tank

Close up of the holes showing the two hoses and the other hole for the tank drain port.

Tank shoved back into it's hole after changing the pump

I have to do the same job on my MY94 XJ12 (XJ81) car since the main fuel pump in that car recently quit.
Fortunately on the XJ81 cars since there are two fuel pumps, a main one and a secondary one, it is possible to swap the electrical leads between the two pumps to make it back home.
Anyway as I do the same work on the XJ81 car I will also take some more photos and make a video of the process.
One set of photos that I neglected to get is any detail shots of the work that has to be done under the car to disconnect the hoses from the bottom of the tank.

 

I did the fuel pump on mine last week; I found the easiest way to deal with the clips on the fuel lines was with a small to medium size flat blade screwdriver with a blade about 1/4" to 5/16" wide.
Previously I'd used a very long needle nose pliers, but using the screwdriver I found it easier to insert the blade under the protrusion of the clip and rotate it anti-clockwise. It doesn't need much of a turn to bring the clip out of the locking slot, less than 1/4 turn.

After the clips were unlocked, starting with the larger line I looped a 3' length of wire over the fuel line (close to the fitting) so it reached well down below the drive shaft and gave it a good sharp pull. Repeated the process with the smaller line. It's a good idea to release the handbrake so that the cable is slack while you work back there - it allows a little more wriggle room for your arm to pass.

Like many people before have said, DO NOT remove the clips, just rotate them. Once the tank is ready to be installed, put the clips back to the locked position, that way the fuel lines can be pushed in either by hand or with the help of a piece of wood. They just snap back in.