Start at the left side of the screen and you see the red beam, you will need to click on the mirrors to turn them different directions in order to get the beam to go where you want it to go, you will need to turn mirrors until the red beam goes into the red sensor which is located at the top right of the screen. Once you have the red sensor done, move on to the blue beam located at the bottom of the cornfield, continue clicking the mirrors until you have the beam in the blue sensor at the right side of the cornfield.
(See Picture Solution below)