The IAC can be removed from the top on the 2.0 engine fairly easy. I recently replaced the one on my 99 Mystique.
Working from the drivers side of the engine compartment:
(1) remove the air tube that runs between the air filter box and the air intake box on top of the throttle body. (just loosen the the hose type clamps and it pulls right out)
(2) remove the air intake box from the top of the throttle body (remove the 3 bolts on the top of the intake box and lift it off the throttle body)
(3)the IAC can be seen from the drivers side at the back of the engine below the throttle body. Unclip the wiring harness and remove the 2 bolts from the IAC.
Keep in mind the IAC is in a tight spot. You will need a socket extention to reach the bolts for removal. The top bolt can be easily seen and removed. The bottom bolt I could not see from the top of the engine, just feel around underneath the IAC and guide the socket onto the bolt.
This replacement is fairly easy to do. I am not a very good mechanic, but I like to try to fix things myself if at all possible. After I fould the IAC it only took about 20 minutes to remove and replace.
The IAC was not available at any of the local parts supply stores in my area. Autozone and Advanced both said it was not available. I had to order the part from the Ford dealer at a cost of about $200.
Good luck.
