You can download these instructions as a PDF here: 66-77 Early Ford Bronco Rock Sliders Installation
Installing the Early Ford Bronco Rock Sliders
First, determine which Ford Bronco rock slider is to be installed on the driver and passenger side. Each guard has a small notch removed from the inboard side where it makes contact with the backside of the rocker panel. This notch should be at the end closest to the front tire. The cutout is slightly oversized to allow for adjustment of the slider front to back.
Next, hold the guard up to the corresponding side. It is best to have a friend help for this step.
The rock slider should fit snug, so some persuasion may be necessary. You can also use a floor jack or high lift jack to hold the slider in place.
Make sure the slider is positioned to your liking, there is a small amount of adjustability available. The forward most hole is used to bolt the rocker on with the 1/4” bolts provided. The rear most hole also gets a bolt to fasten it on. The rest of the predrilled holes in the guard, on the front and back side, are for the sheet metal screws. Drill a small hole through the rocker panel to get the screws started. It may be necessary to remove or lower the secondary tank to make room to install the screws on the back side of the rocker. Repeat for the other side. These guards were designed to protect the lower portion of the body from rocks and other trail obstacles. They were not created to be a step for accessing the vehicle. By using them for this purpose, there is added stress placed on the mounting hardware which was not designed for this type of use. The fasteners could distort the body and the sliders could start to separate from the body.
NOTE: The early Ford Bronco rock sliders are NOT designed to be used as a step to enter the Bronco. Using the nerfs as a step could cause damage to both the rock sliders and the body of your Bronco.