Yup, plastic fasteners are usually one-time use. You don't have to drill much, just enough to break the hold the plastic pin has and they pop out. If you want to put them back on, you'd need to buy some pushpins from a local autoparts store. I guess you could go the plastic rivet route again if you wanted.
'06 XK Limited HEMI 4x4 - 2" Rough Country, Spidertrax spacers with JK Mountain Edition wheels, (5) P245/70R17 BFG Rugged Terrain T/As
'06 LJ Rubicon - built
'65 Corvette convertible
'09 V-Rod Muscle