If your not pulling the tub remove it from the bottom.
I prefer to put it on tall stout jack stands and remove the tranny/transfer cases together with a tranny jack. You can rent a tranny jack to do the job. Don't make it to high that the tranny jack won't reach.
If your clutch is ok then just replace the clutch disc, pilot bearing and throwout bearing while rebuilding the tranny/transfer cases.
I suggest you order the parts AFTER tearing everything down so you know what you really need. Don't buy a kit, just order what you need and for a good rebuild only use NOS or American made replacement parts. DO NOT USE PARTS MADE OVERSEAS, if you do you will regret it and be rebuilding the tranny/transfer cases again soon. Inspect the cases and measure everything to be sure they are not cracked or worn out. If in doubt replace anything that is questionable.
You can get quality parts from Novaks, Peter DeBella Jeep Parts and a few other places but be sure to specifically ask for NOS or American made parts and send them back if they are not.
This link is a good resource for rebuilding the tranny/transfer cases, use it.
http://www.novak-adapt.com/knowledge/t90_rebuild.htm