How do I install this brush guard?

[Envoy99]

I found a guy on a local marketplace selling his non-running envoy, He has agreed to sell me just the brush guard off of it for $100 which seems like a good deal to me. (pic attached is from the listing).

How do I install it on my envoy? Do I just attach the bracket to existing holes then the guard to the bracket or is it more complex than that? I couldn't find any guides on the site.
Also, how bad is this going to hit my MPG?

I'm also looking to add a light bar to it once I get the brush guard installed.

 

[TollKeeper]

You have to be sure to get the mounting hardware, where it wraps all the way around the bumper, underneath to where ever it mounts to on the frame/cradle/radiator mount/whatever. Dont forget to get the bolts too. As far as I remember, its kinda just plug and play.