Unscrew the 4 phillips head inserts and the outer part of the clip will then essentially fall out.
edit: oh yeah. When re-inserting them, be careful not to bend the little 'ears' out when inserting the clip back in the hole. You don't have to screw the phillips head part back in, just push it in the hole.
Crap... Worse case, You're gonna have to go buy new ones and break those out.
If you're lucky you can get a mini flat head (or a pick tool if you happen to have one) and, with finesse, lightly pry the middle phillips head part out of the outer snap while unscrewing it. Maybe you just have to give it a little help to start unscrewing.