Testing a wiper motor

Are you installing it from the outside of the car? I ask this because I have a 3speed wiper on my dart that I installed the lever on the motor 180 degrees off. Now instead of stopping in the down position they stop in the up. I need to unbolt the arm and turn it 180. Just not sure if it can be done from under the hood.
You should be able to do it from under the dash.