I did this on a 4 post ramp using a gearbox lifter & tall (5ft extendable) axle stand on a R33 GTR.
First thing unscrew gear lever knob then remove gaiter & surround (2 screws behind ashtray) it just pulls off. Unplug the cig lighter connectors.
Remove 4 bolts holding rubber gaiter. Pull off smaller gaiter & remove circlip, pull out gear lever.
Underneath the car unbolt the front propshaft from front diff ( you can't remove it yet).
Drain transfer box & gearbox oil.
Undo the hydraulic pressure pipe from the rear of transfer box & blank off with something suitable!
Undo the rear propshaft from the gearbox. Remove the CAT or de-cat pipe.
Remove the exhaust mounting from gearbox.
Unclip speedo drive wiring plug & pull off breather pipe from top of transfer box.
Support gearbox with stand & remove gearbox mounting bracket & the rubber mounting bolted to gearbox.
Lower gearbox, it will drop about 4-5 inches (12cm) now you can remove front propshaft. It just pulls out of the transfer case.
Remove the hydraulic pressure piston assembly, my piston was completely out & cocked over causing the clutch (what was left of it) to be engaged all the time.
Refit the piston if this is the case.
Back inside the car unbolt the gear lever retaining plate (6 bolts) you will need a universal joint on 3/8 drive sockets to remove the front 2.
Lift out the plate, I had to tap mine from under the car to free it (there's a handy lug on drivers side).
Remove the two bolts at the front of the aperture (one 14mm & one 12mm)
Now knock out the roll pins from the selector. There is a thin one inside a thicker one.
This is quite tricky as you cannot get straight onto them even when selecting 1st gear.
I used two long drifts (one for each size) & bent them round. You can only knock the inner pin so far in second gear before it hits the drive chain.
Shove the selector into neutral & knock the pin out. You might be advised to slide a cloth in to catch the pin at this point.
If you can catch the pin all well & good, if not it just drops inside the transfer case & can be retrieved later.
PLEASE NOTE there is a remote possibility of it going into the gearbox!!! you have been warned.
Now knock out the larger pin, it doesn't have to go all the way out, just enough to slide off the gear lever selector from the shaft. You have to slide the shaft forwards to do this.
Back under the car remove the bolts holding the transfer box to the gearbox. they are all 14mm spanner size.
Now support the transfer box & slide it back. The gear selector shaft is the longest part to clear so push it forward if you can.
When the transfer box is on the bench (or floor in my case) you have to remove the pump. Undo the bolts & 1 torx drive & ease off the pump cover.
Slide off the inner impeller from the shaft & remove the two dowels that it locates on
(they are quite loose).
Now unbolt the front casing from the transfer housing. There is one very long bolt & another which isn't obvious almost opposite to where the front prop slides in.
Ease off the front casing, a few taps with a rubber mallet helps!
Pull out the shaft to the front prop, it is a bit tight but comes out with a bit of jiggling.
You can now remove the shaft & the chain. I put the chain back the same way it came off so take note.
Remove the large circlip retaining the clutch pack, quite easy with a large & small screwdriver. Tip up the transfer case & remove the DEAD clutch pack.
Fit new clutch ( I used RK Tuning modified clutch, Neilo gave advise about this) .
Refitting is pretty much a reversal of removal.
DONT FORGET to retrieve any roll pins that dropped into the transfer case!!!
I highly recommend putting a rag under the selector shaft when refitting the roll pins. If you drop one you have to take it all out again!!!
I started the large pin in the selector before fitting to the shaft & held the small one with small Vise Grips to get it started. Much easier than removal.
I used blue Hylomar to reseal (no gaskets).
Refill transfer box with ATF & gearbox with oil of your choice (Redline heavy duty shockproof for me).
Short road test & recheck oil levels etc.
Job done. ONLY took about 9/10 hours in total.