For the rear flaps.....remove the three screws that hold the black piece in the wheel well and the rear bumper together.
For the front flaps.....remove the two screws that hold the black piece in the wheel well and the fenders together. They did require drilling in the front. I drilled into the rocker panel and attached it there too. You couldnt see the where I drilled it unless you where under the vehicle.
Once you hold the mudflap up where it is suppose to be you will see the screws that need to be backed out to install it.