Arghhhh
The clips kinda look like a cloths pin(I know, bad example) and there should be one on each light. The other side of the light should have little tabs that line up into a slot. They literally pop in and out. However, if they start poping out regularly there is a little metal clip on the plastic clip that is probably loose or bent.
This could be a little off as I'm just trying to remember and picture this from over 4 months ago.
Oh, and they are OEM
http://vertexracing.com/images/produ...248695-n-k.jpg
If you look at the left of the light you'll see where the metal clip thing would be. It's right in between the cloths pin looking clip.
Maybe it got loose and fell out if it's not there on your lense. If thats the problem then it will only fall out more and more. Not sure where you could find that small part. So So quality clear lenses cost about $30-40 a pair. The OEM units about $70-80 I think.



At least it didnt scratch up the paint or rip out the wires