Do this modification at your own risk!!!! You need to ensure car is properly on Jack Stands. I only show you what I did that worked for me, I have a ton of experience working with tools, fabrication and cars.
Other DIY you may want to look at as well:
DIY: Whiteline rear differential bushings
Tools you will need:
1 - 12mm open end wrench
2 - 17mm open end wrenches
1 - Deep 15mm Socket w/8 inch extension
1 - 14mm socket
1 - Breaker bar or piece of pipe that will fit over your ratchet
2lbs Hammer - short handle if you have it.
Floor jack
3/8th drill bit
Sawzall with 6inch metal cutting blade
Something you can use as a punch (I used a broken 1/2 extension)
Spray lubrication (I used stuff that is a rust inhibitor and lubricator for aircraft)
Special Tool See Images (make it)
Step 1:
Remove Exhaust from Y pipe back.
Step 2:
Remove the frame supports & rear sway bar. Clean and re-lube sway bushings.
Step 3:
Us 12mm end wrench and remove the drive shaft protection shield. If you skip this like i did just bend it down if you need to.
step 4:
Undo the 15mm bolt using the beep socket and extension. The location of the bolt is on the back of the diff cover. You will need to access it from the rear of the frame support behind the diff.
I you can get it off, get a breaker bark or slide a piece of pipe over your wrench. Once it pop's you will think you broke it. As soon as it's free it spins easy. Completely remove bolt.
Step 5:
Using your 14mm end wrench (I used a ratcheting end wrench) undo the axle shafts from the side of the diff flange. 6 bolts - may need to use your 17mm wrench to spin the drive shaft to access the top bolts. Tie the shafts up so they don't slide out.
Step 6:
Okay,
To remember where your drive shaft is take a paint pen of file and make a mark on the drive shaft flange and Diff flange. This will keep everything lined up when you re-install.
Use your (2) 17mm end wrenches and undo the 4 drive shaft bolts. You may need to spin the drive shaft to reach the upper bolts. For AT undo safety break and put transmission in neutral.
Step 7:
Use your 12mm end wrench to undo the 2 sensors. (1) on each side, push them up and in a place they wont get damaged.
Step 8:
Slide the floor jack under the rear diff. The rear is heaviest thats the best spot to set floor jack.
Step 9:
With Drive shaft off, Axles off and tied up, floor jack in place; undo the last 2 15mm bolts holding the diff up. Slowly lower it far enough to access the breather hose on the diff cover. Pull it off & tuck it up and out of the way.
Lower diff and pull it out.
Step 10: Using your punch & 3/8 drill bit (i used 1/2 extension) drill and beat the crap
out of the old rubber bushing on the diff to remove them.
Once you get them off, put the thin Whiteline bushings on the top and thick bushings on the bottom. Fallow the instructions on your kit, lube pins up to make it easier.
Step 11:
If your bushing on the frame hasn't burst yet you will need to drill hole on top and bottom on both sides to get the liquid out. Use a oil pan and a rage to keep the stuff from blowing out all over you.
Drain the fluid, when done keep drilling out the rubber. Your trying to make a spot large enough to fit your sawzall blade.
Step 12:
Using your sawzall position it were you can cut flush all the way through. I did it from the rear of the car and cut strait through the bushings side wall.
Once cut use your punch (I used 1/2 extension) and pop the ring out. Clean the side walls to prep it for next step.
Step 13:
Your directions tell you to bolt the sub frame bushing on to the diff before install. One word for you ( NO )!!!!
I took a piece of angle iron, 6 inch 3/8 bolt & nut & washer and made a press to get the bushing in with out damaging it or my calm nature 
. Attached is the image of it. The angle iron and bolt are set on rear of car. The bushing is slid over the bolt. I used the 3/8 washer and the thick washer we removed from the diff bolt and using a ratchet end wrench and hammer i tightened it in to place. May have to tap the washer to align the bushing as it goes in to position. Took 5 min.
What bushing looks like on the tool:
What the bushing looks like on the tool & on the car getting pressed in:
What it looks like almost done:
What it looks like done:
When you go to put diff back in it takes 10 min when the bushing is in already.
Step 14:
Put it all back together in reverse order
.... Done
The order the washers go on. Metal washer goes on top and needs to be slide in place once diff is back up in position.
Warning: Used the proper torque specs for your drive shaft and axle bolts. This is under extreme load and is not to be taken lighting. I mark each bolt after torqued, will recheck after a few drives to work and back.
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