I did want to mention that this turned out to be much more difficult than I expected; of course, some of the pain was self-inflicted. Here are some tips:
1. You can get the lines on and off by removing the battery, battery tray (remove horn to get to front bolts), and the bolts holding the fuse box, and disconnecting the two ground wires from the body. I also disconnected the air conditioning line mounts and several clips holding the wiring harnesses.
2. Removing the old cup seals was a real pain. I tried several different ways to get to them before I found a way that worked. I ended up buying a seal puller and working from underneath. There is an opening behind the rack where I reached in with the puller. I was able to barely get my left fingers to the seals to guide the puller into the openings and use my right hand to push the puller forward to pry the seals out. It was completely by feel. I then used a flashlight and a mirror to verify the seals were out since they disappeared (until I later found them while looking for other dropped things).
3. In my case, I am pretty sure I would have saved time if I pulled the axle. I didn't do this since others that posted did not seem to have a problem with the axle in. It is definitely not necessary, but I think it would have made it easier to get to the seals to pull them and to reinstall the lines, and since I ran into problems, it would have saved me time in the long run.
4. You can access the lines at the rack connection from the top of the engine. I did not realize this at first, but after having issues putting the new lines in (having the cup seal pop out while trying to push the lines in, dropping the seal and losing it this time so that I had to buy a new one from the dealer, dropping the 8 mm retainer bolt and spending an hour looking for it, etc.), I tried installing the the cup seal and new lines from the top, and it was much easier. I just removed the brake booster vacuum line to make more room for my arm, and then I layed on top of the engine and reached in with my left hand.
5. Put shop towels and/or cardboard below the the rack connection before removing and installing the lines and seals. Before I did this, I dropped things (bolt, seal, and tools), and they would vanish. Although this was meant to make it easier to finds things when I dropped them, this seemed to cure me from dropping things.
6. Working from the top of the engine, it is not that difficult to push the lines through the cup seals. I was nervous that this might be difficult and I might damage the seals doing it, so I tried to buy lines with the o-rings instead of cup seals. When I went to install the aftermarket lines from Advance Auto, only the pressure line had an o-ring. Even though the return line was supposed to have an o-ring according to the part description and the instructions that came with the line, it came with a cup seal instead. I returned it, but none of my local part stores had the return line with an o-ring in stock, so I ended up trying the cup seal. I think it may have helped since the line stuck in the seal after I got it started by hand from above. This allowed me to go in through the wheel well to pry it in farther with a screwdriver, and the lines stayed in place when I worked from the top to get the bolt started. I think the cup seal helped keep the lines from falling out. I then used a ratchet and extensions on top of the axle as others have recommended to install the 8 mm bolt.
7. This is obvious, but pay attention to the line routing before you remove the lines. Maybe take pictures. I initially routed the pressure and return hoses that go to the rack between a wiring harness and the back of the strut tower. After connecting the lines to the rack, I realized that they needed to go over the wiring harness to avoid rubbing and to allow the lines to fit properly.
8. I could not get any of my tools to fit on the front mounting bracket bolt that mounts the pressure and return lines to the frame on the driver side, near the front of the engine bay. GM decided it was a good idea to put the bolt between the lines to block access for a wrench, and then align the center of the bolt with the body so that even my 1/4" drive ratchet would not fit. I put a small 10 mm socket on the bolt and used vice grips to turn it. I wrapped electrical tape around the socket to keep it from getting scratched up by the vice grips.
9. I removed the mounting bolt near the crankshaft pulley with a 10 mm wrench from the top, squeezing my hand in the small space and turning the fan while I turned the wrench. This would have been less painful if I had removed the fan, but it would have taken longer. I installed the bolt the same way but from underneath with the truck on jackstands, and while this took a little longer than from above since I could not see what I was doing, it hurt less.
10. Be careful with the stud for the battery mount. I had the battery out a few times before with no issues, but for some reason, this time the stud decided it was going to unclip itself and fall into the wheel well.
11. Removing the air box and windshield washer fluid reservoir is easy and makes it really easy to get to the power steel pump connections.