Piece of cake Cantaloupe. If your gauge reads anything under full, you don't have to worry about fuel spilling out. Just be SAFE first, no open flames, sparks, friends welding nearby, or smoking during the fix.
Loosen up the hose clamps as far as you can loosen them first, take it all the way off first if you can. From the pic, the hose clamps you have are the type that will not come all the way off by unscrewing it, so unscrew it as far as it will go first. Spray some wd-40 type oil on the clamp, and cover the rotted hose in grease if you can, this will help hold the rotted out rubber in place. (you do not want any pieces of rotten rubber getting into the tank). Let the oil sit on the hose-clamp for at least a few minutes before trying to remove / unscrew it. It looks like it's been on there forever.
Once you have the hose clamps as loose as they will get, you can start to push the clamps in the opposite direction of the gap that SHOULD appear once it's loosened up. This will break the clamp completely free of the hose. Take your time and study what is going on as you go.
Once the clamp will spin freely around the rotten lower hose, pull it UP and out of the way of the steel filler neck. At least 4 inches or so. You can hold it there or tape it up, so the clamp is out of the way. Then take a SHARP razor blade and CUT the rubber either up and down, or feel for the metal underneath, and cut the rotten rubber off flush with the metal gas tank tube beneath it.
It is important that you don't let any rotten rubber pieces fall into the tank. The old hose should just peel away from the steel / metal tank nozzle once you have cut a slit with a SHARP razor blade.
You will need to remove the upper part of the hose as well, you can do it before or after, and use the same procedure. But since the hose is so rotten, I would cut the lower part off first, then cover / tape the metal filler tube to the tank shut. Just wrap some duct tape or masking tape over the metal filler tube to keep dirt and rubber from falling inside. Then cut away the top of the rubber hose from the metal at the top filler tube.
Take some Scotch-brite or sandpaper and clean the metal where the new rubber fill hose will go, top first, then remove the duct-tape and do the same to the bottom. Put some grease on the outside of both of the metal filler tubes, put the bottom filler tube on the tank first, then slide two NEW hose clamps on the new rubber tubing, and then install the upper tube to the metal gas filler neck.
Slide the new hose clamps on, and SNUG them up, they don't have to be super tight, just snug. If you see rubber pushing out of the little slots on the new hose clamps you are overdoing it. We all have a tendency to over-tighten things, especially when we are young...so watch it.
Your hardest part is going to be getting the factory rubber hose, you can order it from specialty places on-line, or call around to find an auto parts place that can order it. You could also just get the correct diameter rubber hose if it's a straight line shot from the filler neck to the tank, but that is rarely the case. Most of us would just spend the extra money and time, and order the correct hose. You may also find a small hose inside of your filler hose, this is to allow air to escape while the Gasoline goes in. If you have the small hose inside of your large filler hose, you better get the right replacement hose, or you will spend 20 minutes trying to put gasoline into your tank every time you go to fill up.
I did this once when I was young, I cheated and just used a radiator hose that fit my tank and filler tube. Whenever I went to get gas, the pump would keep clicking off every 3 seconds or so, because I did not re-install the little air hose (burping tube) that goes inside of the big hose. Your truck is old enough that it may not have this hose, but I don't know. I do know that it sucked to spend 20 minutes to put 5 gallons of gas in my truck because I did not spend the extra $20 on the right parts.
Anyway good luck, you can do it!
