I removed the nipples from the fuel tank. One looks pretty good, but the other...not so much. As you can see in the picture it's torn up and jagged and the nut doesn't want to go back on easily. I'm afraid if I try to force the nut on there I'm going to damage it more. Is there an easy fix for this? I'm a real novice, so be gentle with me.

In the front is the pre fuel filter insert.
Pull these filter out and it looks like the other.

The part that your concerned with is the sealing ring on the filter sock. Pull it out and replace it.

should I pullout the other one too? Where do I get a replacement?

I just yanked it out and I see there isn't one on in the other. So I guess that's the fuel strainer screen I see in there? How do I get that out...from inside the tank or thru the hole?

The screen is only on the supply side which goes from the Fuel Tank to the Fuel Filter and then the Fuel Pump on the 75-76's if you have a 70-74, I do not know the sequence. To remove the filter sock that remains you can excess from the top of the fuel tank, if you remove the cannister above the fuel tank. If you have removed the tank then it's obvious how to get it out. The part (Fuel sock filter) is not expensive and very available, make sure you have the proper seal/washer when replacing the fuel nipple. Also this is is great opportunity to clean the gas tank up. POR-15 has a great system, if you decide to reseal the gas tank...use gloves.

Good Luck