Here is what I did for the rear suspension remove and install. I replaced my stock original shocks and springs with KYB GR2 shocks and RSR lowering springs. They lowered about 1 3/4 inches.
If you are interested in the front suspension install, see my other post here:
You will need a spring compressor, ratchet set, wrench set, door panel puller, torque wrench and an optional impact wrench.
Remember to have your alignment checked after doing suspension work.
I followed the Lexus service manual with the exception of the brake caliper, which the manual said to remove but I did not. You'll see pictures of how I got the shock out without taking off the calipers.
1. REMOVE LUGGAGE COMPARTMENT TRIM FRONT
COVER AND FLOOR MAT
Use a panel removal tool and pry off the 4 fasteners on top.
Remove the trunk mat and pry off the fasteners at the bottom.
Here's what's behind the luggage compartment trim.
2. REMOVE REAR WHEEL Torque: 103 N·m (1,050 kgf·cm, 76 ft·lbf)
Jack up the car at the rear cross member (do not lift by the differential near it)
Support both sides with jack stands at the jack points listed in the owner's manual
3. REMOVE REAR BRAKE CALIPER (I DID NOT DO THIS, though it is easier to get the shock out of the wheel well without the caliper)
(a) Remove the 2 bolts and brake caliper from the rear axle
Torque: 104 N·m (1,065 kgf·cm, 77 ft·lbf)
(b) Support the brake caliper securely.
4. DISCONNECT REAR STABILIZER BAR LINK
Remove the nut and disconnect the stabilizer bar link from the
No.2 lower suspension arm.
Torque: 44 N·m (450 kgf·cm, 33 ft·lbf)
5. REMOVE SHOCK ABSORBER WITH COIL SPRING
(a) Remove the nut and bolt on the lower side of the shock
Torque: 137 N·m (1,400 kgf·cm, 101 ft·lbf)
At the time of installation, after stabilizing the suspension,
torque the nut.