This works for all VR & VS Commodore models and should work for Statesman or Ute as well. Not sure about models not fitted with Climate Control though...
First of all, turn the engine off.
Put the gear shift into D, and make sure the hand brake is on FULL. Undo the zipper on the hand brakes booty.
Open the center console, remove the junk, and remove the carpet.
Undo the 2x 10mm bolts holding the back of the console down.
Lift the console up ~10cm and pull it backwards, some jiggling maybe required. When it has slid back ~1" it will be back far enough and you should be able to see 3 Phillips head screws, remove those screws. The fascia will now lift out, remember to unplug the buttons on the fascia otherwise it won’t come out.
Remove the 2 clips retaining the under-dash guard. Turn them 90 degree's with a flat head screw driver and they will pop out. The entire unit will now fold down (its hinged at the base). On the left side area you just uncovered there are 3 Phillips head screws retaining the right side of the console, remove them.
Open the glove box, on the right side of the open area are 3 more screws holding the left side of the console in place. Take them out.
There are now 2 screws in the middle, under the headunit, holding the console in place. If you have Climate Control, there are 2 screws on the left of the CC unit, remove those. The CC unit will now lift out (again, unplug the plugs from the back). As will the rest of the console.
Undo the 2 screws retaining the headunit. Remove the OEM adapter plates, the holes will need drilling out to a large size in order to mount to a standard HU (such as Alpine or JVC).
Installation is the reverse of removal. When re-connecting your Climate Control unit, make sure you hook the mini-duct to the back of the unit when re-installing it! This duct flows over an air-flow & temperature sensor and is used to control the CC functions in the car, the AC will not operate correctly without it.