The first thing you need to do is rotate those fenders so they pass below the head tube. There should be a bracket in your package that wraps around the fender, and mounts to a hole in the top of the fork where center pull brakes would mount, if they were being used.
Then loosen all the stay mounts, and slide them out until the fender is about a half inch from the tire. Take off the plastic caps. Tighten the stay mounts (this is a good place to use thread lock). You'll want to cut the fender stays short, just a bit past the nut. You may be able to do this with some sort of lineman's pliers, or just use a Dremel. I'd suggest you take a file or sandpaper and round the edge of the stay, because the plastic caps won't really stay on. Then put the caps back on.