I've done this job on my 93, it's the Regina or GM crappo fuel pump. No smoking while doing this job, tank and other stuff is plastic, so chance of spark is low, keep garage door open, if possible, although it was a winter when I did mine and door was closed.

This puppy is quite tricky to get out of the hole, you need to twist and pull or pull and twist while holding extension up or down. Sorry, but I can't remember the whole routine, but patience is a must for this one. If you start getting ticked off, walk away for a while. As for the rubber seal, you either put it in the hole and slide unit in or put in on the unit and slide it in. It goes in real easy one way, but real hard the other, it will be obvious. Disconnecting the lines and re-connecting them is straightforward.

For what it's worth, this is not a job where you want to go used. These GM pumps aren't the greatest to begin with, and I doubt you'll want to repeat this job in 3 months. But, if you still want to go used, you'll have to solder the connections once your pump is installed on the sender. Again, personally, I'd go with a new pump on your sender if money really is the issue, or better yet a complete new unit ($$). This will make sense once you get started on this. Good luck.

Mike