My concern is with the dent you have, it's more of a bend. You need to find a way to flatted it, and than use that tool, my concern is if you use that that , you will bend it more . Sometimes you can make things worse 🙁
Correction : there is a tool from them that also flattens the bend first
Also , check eBay, a top cover can be had for under $100. The tool is $140? I'd go a replacement cover. No matter what you do with the tool, it will always have a bend/dent