step 1: sell car.
step 2: buy AE86.
This can be very expensive converting it, unless you are willing to do all of the work yourself.
For example, there is a guy who tried to sell his AE85, which he had spent 15 grand on to get it to AE86 spec.
Of course this becomes significantly cheaper if you do the work yourself.
And after all this, it still wont have the value, or street cred of a geniune AE86.
Bah! But you probably know all of this of course.
To answer your question, I believe you need a new engine, gearbox, diff, springs shocks and struts.
You need to find a RWD 4AGE, (manifolds etc are different from FWD engine)
t50 gearbox,
dunno about the rest.
I thing there was a factory LSD for the AE86?
Im sure this topic has been covered several times before.