If you don't have the "proper" tools (spring compressor) and have access to air tools and you aren't worried about reusing the stock parts: once they are out of the car, wrap the coilover TIGHTLY with a towel making sure to cover the top as well. then just zip off the nut. The towel will keep the parts from shooting apart.
On the rear removal & install... disconntect the lower control arm from the spindle (both sides), have a ratchet wrench (15mm) for the inside forward most bolt holding the top on.
Also, as you drop the rear coilovers, turn them 90* and they come right out.
On the install for the rears, install the 4 bolts just enough to hold the coilover (do both sides before proceeding to the rest of the rear install), then position them in the lower control arm, do both sides then install bolts, then attach to spindle, then tight everything.
ON REASSEMBLY, NO AIRTOOLS ON THE ENDS OF THE COILOVER MONOTUBES.
If I think of anything else, I will let you know. Intersted as to your opion of those as well.
2SS/RS 400RWHP, Hurst Shifter, Vararam Tune model,SLP Loudmouth axle back, Pedders Camaro Pace Car Kit &, EP7323, PDUSACAM2800, EP1167, ZL1 Calipers, CTS-V rotors, ZL1 Wheels, GTO clutch resevoir, Pedders Camber plates.
Back Street Performance
has done a great job with ALL my Performance & Suspension mods, highly recommend them (Rich@BSP) he's in my friends list.