I've done this job to three or four of my 240s, and I can tell you my approach. This may or may not be a way that you want to try.

The main fuel line (from the tank pump) disconnects at the top of the sender -- no problem.

But the fuel return line, which is black plastic (and is inside the protective black foam rubber sleeve), is shrunk-fit over a barbed fitting at the sender. I usually cut back 6"-8" of the foam covering.

Using PLENTY OF FORCED FRESH AIR past the sender (e.g., a fan), I use a heat gun to warm (NOT melt) the black plastic where it's shrunk over the barbs. After 10-20 seconds it's soft and can be pried off the barbs using a screwdriver.

(I use the fan to insure that fresh air is moving past the heat gun, which creates sparking in its small motor. You don't want gas fumes around sparks.)

Then you go about your business with the sender, twisting, turning, cursing, knashing, pissed, magic words, etc.

Once you're finished and the repaired sender is installed and locked down, reattach the wires and the pressure fitting. Then slid the black plastic hose over the barbed fitting and secure it with a small screw-type hose clamp. It carries no pressure so shouldn't leak.

I don't recommend for or against this approach -- it's how I do this job.

--
Don Foster (near Cape Cod, MA)