Very common problem. I have not had to do this on the kdx (yet) but have on two other Kawasaki's, a Buell, and a Yamaha.
Drill off the heads carefully. You want a drill that is almost as big as the outside of the stripped screw shaft.
Drill a little bit at a time, until the head comes off, then stop immiately. The master fluid reservoir cover will then lift over the remaining shafts. Once that cover is off, you have relieved some strain on the screws, and exposed enough of their shafts to get needle nose vice grips on them. They then usually come out easily.
Then either order new screws from Kawasaki, or go get a close match at your local hardware store. But use anti-seize this time.