There is the threaded holes under the bottom yoke (tree) x3 needed for the mudgaurd. As part of the fitting kit you will need the spacers too. Maybe these will come with the fender but be sure to ask, plus as mentioned the bolts.
I've fitted a high mount fender to a Classic, I know it's not an Icon but the Classic has a low mudgaurd similar to the Icon only steel so I'm certain it will work.