You can DO IT!
I just did what you're talking of doing in my 93. Its not as hard as it may seem. On the seat the buckle portions are different since the lap belt isn't needed on the newer interior. These are easy to swap...just held onto the seat frame with 2 10mm bolts.
As for the rest of the project, you will need all the trim pieces for both sides. Obviously the rear panels for the seat belts and also the pillar trim since the auto belt is no longer going to be there...without it it will leave a gap.
All mounting points are already in place accept 1, that being the top mounting point for the seat belts....you will understand what I mean when you get there. I just drilled a hole a bit smaller than the bolt and let the bolt tap its way into the metal.
If you have any hang ups, let me know. Oh and if you need some pictures look for my thread on the interior swap.
-Tim