The clips themselves are built into the fiberglass valence piece. They snap into a hard rubber or plastic "cup" that is replaceable, but the clips themselves are not due to being part of the fiberglass part itself. If you break them, you'll need a new valence or to glue it back together depending on how it shears.
For what it's worth, it took a REDICULOUSLY hard bit of pulling on mine to remove it after 20 years in place. Got the center valence out okay, but broke both headlight fiberglass trim bits which use the same damn clips. Had to glue them back together and now have come crack lines as a memory of my project.
Sprayed some WD-40 on the clips before reinserting in hopes of making any future ordeals at least a smidge easier.
Thanks for the response - did you break the headlight trim pieces when removing the front valence, or when removing them after the front valence was off? The reason I ask is I am just as (if not more) concerned I will break the tabs on the headlight trim pieces it appears the front valence partially connects to.