Its really easy actually. The center of the black clip is actually a "pin". Carefully take a pair of needle nose pliers and pull out on the small raised part in the center of the clip. it will come out about 1/2 to 5/8 of an inch and stop. I push down on the larger part of the clip while pulling the center to keep it from moving around.
After the pin is pulled out, carefully pull on the clip to remove it from the hole. Don't worry if you happen to pull the center pin completely out of the clip. The pin will pop right back in when you go to reinstall the clip.
Hope this helps.