if its a 90 i take it its a rear wheel drive?
if so then its easy, as you look at the engine it sits on the left hand side,
you can do the whole job from above, no need to go underneath
just make a note of the route of the fan belt before you take it off
as its huge and is hard to remember
should take no more than an hour
but check the wiring as they are bad for braking wires causing bad connections etc