The GM shop manual has good instructions on how to R&R the rack. You will have to remove the front sway bar to get to the bolts holding the rack in place. You will need a metric "crow's foot" (18mm I think) to remove the pressure hose from the rack; you can see this hose connection by looking down in front of the A/C compressor. You'll need about 2 feet worth of socket extensions to get to it from above. It's next to impossible to get a open-end wrench on it!
If you have a tie rod puller ($6 at Harbor Freight) use it ti remove the tie rod stud or remove the castle nut and turn it upside down and re-thread it so that the nut surface is even with the stud and use a hammer to knock out the tie rod end.
When you go looking for a replacement rack, make sure they understand you need the quicker-turning rack. Most places should have refernces in the parts book to the two different versions. The listing will say something like "with HD suspension", "optional sport steering" or maybe even "Z51" or something like that. The Z51 rack is typically more expensive. There will be a core charge (usually $100-150).
They will probably tell you that you have to return the "correct" rack, but there is no easy way to externally tell the difference between the two. Factory racks have different numbers on them, but rebuilt assemblies from parts stores may not have anything on them. Buy the new rack and install it then take the old rack back for the core refund.
Depending on mileage, consider replacing the tie rod ends at the same time you replace the rack. USe AC Delco or Moog. They are not hard to remove from the rack once the entire assembly is off the car. To get the new tie rod ends in the correct place, release the jamb nut and count the number of turns it takes to unscrew the old ones. Also measure a distance from someplace on the old tie rod end to the end of the sleeve. When you install the new ones, turn them in the same number of turns and verify the measurment you took on the old one is the same for the new one.
I would also drain all of the old PS fluid from the pump and reservoir and replace with new fluid. Once you have the new rack in place and the hoses connected, fill the reservoir and start the motor. At idle, turn the steering wheel to full lock to the left and right a couple of times. Stop the motor and refill the reservoir. Let it sit for a couple of minutes and then repeat until the steering seems firm and the pump is quite. Check the reservoir and fill to the proper level. Use a PS fluid and not ATF. I'm using Red Line PS fluid in my 87 for autocross and track days. The synthetic fluid handles the higher temps better that the off-the-shelf fluids. It's pricey at around $8 a quart, but the system only needs a couple of quarts.
Once the rack is in place and everything bolted up, you should have the front alignment checked.
