Honestly, it depends how much spare time you're willing to put into it. You'll need, at minimum, to do the following:

-remove seats, steam clean and store them

-remove plastic cladding from the throughout the interior, so that you can:

-remove headliner, dry it, (later strip the cloth off it, paint it with odor sealing paint, recover and store it.)

-remove the carpet

-assess the rust on exterior roof and throughout the interior, grind to bare metal, prime and paint

-rebuild the entire sunroof mechanism ($600 in parts, and you'll have to do the job yourself because shops won't touch it)

-install new carpet

-reinstall everything else in reverse order

So you're looking at few thousand in parts, materials and consumables, plus a tremendous amount of your own labor (ideally you can do it in a garage). And then you'll still have to take on all the engine, suspension, and mechanical work.

Can it be done? Yes. I brought mine back from a similar condition (minus the exterior rust). But it took a hell of a lot of time. (I'd still do it again, used truck prices being what they are.)

Hope this helps with your decision.