When I replaced my fuel pump last year I used a big flat head screwdriver and a hammer and Liquid Wrench to get that ring off.
I messed up the metal part of it but the plastic part is still good.
I am going to replace the ring with a new one.
Your pump will turn as you pound this thing loose.

My fuel filter was in the same shape as yours when I first got my truck, I took a hack saw and cut the nuts off the filter and pried them off the fuel line.
Now I replace my fuel filter once a year and use Anti-Seize on the threads, takes 15 min now, first time took me 4 hours.

 

My line from filter to tank was also in need of replacement.

Can't find just a top anywhere, can't afford a new aftermarket or used one at the prices the Rover Vultures want for such.

I am applying Good Ole Boy Redneck Engineering to fix mine. Will post pics and details later.

 

Alot of guys have reported the top of the fuel pump cracked and have just gooped it with silicone.

My fuel pump was $450. Ouch man!

 

new pump or else it will leak really bad once the new lines get in place.

 

This is where I am at with it now. I cleaned everything up really good. Got the red ring off with the screwdriver blade seated against a slot and a steady tapping force with a large hammer. It finally got to turning freely.

I ended up cutting the existing metal lines barely above the top surface. Then I used them like a feed-thru. Sanded down the end of some 1/4 vtubing, forced it thru the existing pieces and clamped the inside hoses to the new tubing.

I'll be fabbing new fuel lines from the 5/16 tubing and routing like you said, forward of the wheel well and along the frame to the engine compartment. I'll check for leaks at the tank when I power it up.

If it does leak, RN has a ProComp for $100. Had I known that earlier, I would have ordered it. Since I repaired and reinstalled already, I plan to test it at least. Fabbing new lines next.