You'll need to drill 4 holes in the grill to mount the brackets. Two on each side. Make sure you leave clearance inside for the drip pan, grate, and other components. And clearance outside for the lid and handle. I wish I installed mine just a tad bit lower to give the lid handle a little more clearance. You'll need to find 4 bolts. Make sure the bolts aren't long enough to disturb the inside components. I just used random bolts in my garage and cut them down to size. It was a tight fit on the grease drip side but once I cut down the bolt it was fine.
It will end up installing like this one except you have to drill the holes yourself. https://youtu.be/2skB5GQkc-s