I removed mine today in preparation of installing my Prinsu rack. One thing to note is the cover is very thin plastic. There is a very narrow gap between the base mount and the cover.
I started with a plastic wedge tool but soon moved to a steel thinner one. The steel one fit between the base and the cover much easier. Once the outside end of the cover is popped just push the cover tword the center of the vehicle and it will pop free.
Then you remove the two 12mm bolts at each corner.
Details and pictures on my build thread. It's a pretty easy process, but I wouldn't leave things exposed any longer than needed. Unless you cover things with a new rack or covers, it will be an issue if it rains.