Installing a brake controller unit isn't very difficult. This task is made even easier if your tow vehicle is a late model and comes with a 7-way connector as part of the towing package.
In this case, installation is as simple as mounting the brake controller in a convenient, easy to reach place, usually under the dash, just above your right leg, and connecting the wires from the brake controller to the wiring harness, and then plugging the harness into the harness located under the dash.
View this video from etrailer.com to see how easy it really is to install and test a brake controller. This video shows the installation of the Valley Odyssey brand of brake controller.
Also, here are some basic steps to take for the three popular late model trucks/SUV's: Ford, GM/Chevy, and Dodge.