The front four-bar brackets mount to the frame where the original front spring brackets used to be. There is a difference between the new right and left bar brackets so you've got to pay attention. To figure out which is which just make sure that the lower bar mounting hole in each bracket is further forward than the upper hole. Attach the new brackets to the frame using the supplied bolts and nuts, and snug them up. Next, you'll have to drill two new 5/8-inch holes (one on each side) in the frame through the upper bracket bar mounting holes (they had yet to be drilled in this image). The second image shows the bolts and lock nuts from the inside of the 'rails.