Here is how I went about installing the mounts and light bar.
Remove upper radiator valence. Place mounts on aluminum X-member behind lower grill, bolt up mounts to light bar while behind the grill. Center mounts and light bar on aluminum bumper X-member. Use lower grill as reference to center the mounts and light bar. Mark holes with sharpie once centered. Remove bar and mounts from behind grill. From the back of the grill, unscrew the philips head screws on the lower grill retaining strip. From the front, pop lower grill free, and remove. Use body panel removal tool or flathead screwdriver with tape over the end to prevent scratching your bumper. Center punch marked holes. Insert drill from the front, drill 1/8" pilot holes (4), drill holes out using a 13/64" drill bit. Tap holes using a 1/4-20 tap once drilled. Pop lower grill back in, install retaining strip and screws. Now bolt up your mounts and install light bar. Lock tight and lock washers is highly recommended.