I was just as worried as you before I did my first tank pump swap. The hardest parts are dealing with the rusty hose clamps and figuring out the reinstall process. I've had to pull out my Bosch in tank pump now twice within the year. I had my fuel level at about 1/4 tank both times I did it. Art's pictures were actually quite helpful for getting an idea of what you're about to get yourself into.

Tips:

Do NOT park the car so that sun shines on you from behind if you're doing it outside!!!! I made this mistake the first time around and ended up with a very uncomfortable sunburn on my ass where my T-shirt rode up.

Clear the trunk and remove the felt completely. Leave the spare tire in so you have something to sit on. Your best bet is to sit sideways and turn your upper body towards the hole. If you don't have a mask with a remote air supply, remember to take a whiff of fresh air every now and again and when peeking in don't put your nose over the lip of the hole.

Your hose clamps will be toast. Accept this before you even start the job and buy spares. You'll be a happier man in the end. Also consider a new seal and maybe even new output/return hoses if they're the originals. I tore my ancient 12mm output hose when I pulled on it, but had a spare handy. Loosen all clamps before you start unplugging things.

Use nitrile gloves, the cheapie kind work fine. You don't have to worry about building fancy tools for the plastic ring or hammering it with a screwdriver - just put some gloves on and twist. 3/8 socket extension stuffed inside a glove makes a good plug for that big output fuel line, btw.

Use rope or strong thread & strong toothpick to retract the spring. Waxed dental floss is a no-no, this screwed me up on the second install because it kept slipping and I had to go rummaging through my wife's sewing kit for some strong thread.

The filter sock is the same all around. Once it's on, it stays on quite well. I haven't knocked any of them off during installation yet.

Use vaseline to lube up the inside of the tank seal and any hoses you have difficulty reconnecting. Mounting the pump is mostly annoying, it takes a while to figure out how you can slip it back in there. Reconnecting the hoses is also annoying, because you have to now figure out in which order to put the hose clamps back on so you can actually get to the screws.

Good luck, you can do it!