The same way you take it off! But in a reverse order.
on the steering wheel
Into the power steering reservoir under the hood.
Yes, i own one and the steering wheel locks on me sometimes on accident.
Yes, it's possible.
You don't have an airbag
No. None of the Z32 300zx's have them. (1990-1996) There is no option for it either. The only thing you could do is buy an aftermarket wheel that is smaller.
In the hatch or behind seats
You dont need one you idiot, i will key your ricer 300zx if u ever do that, your a disgrace to all 300zx owners!
Automatic Transmission fluid
The power steering fluid reservoir is up on the passenger side wheel well in the engine bay. Looks like a short fat silver coke can with hoses coming out of it. On a side note, the 300zx twin turbo uses ATF (automatic transmission fluid) not power steering fluid. usually a green casing with black top. the following link is NOT a 300zx, but the reservoir is about the same. http://www.sillbeer.com/images/engine/power-steering-reservoir.jpg
To install a thermostat on a 1987 Nissan 300ZX, remove the two nuts and one bolt on the lower water neck. Slip off the old thermostat and use a gasket sealant to secure the new thermostat.
At the front left side of the engine, if you are looking under the hood.
its on the passenger side silver with a black cap.
Yes>>assuming you use the wire-adapter connection plugs sold seperatly
You can find just about anything you need on E Bay.
four wheel steering warning light
You need to remove the panels in the trunk to get at the top of the gas tank, then you can easily remove the pump and install the new one.
you need to remove the radiator reservoir first. there are two screws you have to loosen on the power steering pump..thats it
best way to do it is from the underside using mostly box-end wrenches
Directly above the Alternator. Its on the passenger side. The power steering pump is attached to the top left belt. Not to hard to get to if you need to.
I don't mean to be condescending but it would be more economical to buy a convertible first.
If I understand right, you want to take shocks from a Subaru and install them into a Nissan. Forget about it. Just purchase new shocks meant for the Nissan.
try wiggling the steering wheel it has a lock on it