Ok it's been a long day and I have a few drinks in me... so please excuse my pending spelling/grammar errors

Replacing the rear springs/shocks is relatively easy. Disconnect the shocks first and install the new ones last since you want the axle to drop as much as possible to help facilitate the spring install.

Disconnect the sway bar, and it doesn't hurt to take the calipers off too (just so you're not stretching the lines too much).

The passenger side is easy.... You should be able to sneak the OME spring in without much trouble once the axle is at full drop.

For the driver side.... if you didn't trim the gas tank skid, now's a really good time. The upper radius arm will hit the skid and limit flex, which makes it hard to get the spring in. You have a few options:
1: use spring compressors
2: disconnect the upper arm (a bit of a pita)
3: trim the skid (i recommend this since it adds capability as well and takes less time

For the shocks you'll want to order Rancho P/N RS999286. Get a bunch of 7/16" washers as well for spacing the upper mount.

If you get stuck or need help... post up or PM me. Pretty sure i have a combination of OCD and AADHD and these forums are one of my outlets, so im never far from offering a helping hand