I bet there's a proper tool but i use carpenters pincers.

If you are careful they can be re-used but sometimes they break up so are useless.

Loads for sale on ebay but finding a identical replacement may prove difficult, unless you go to renault.

 

Using Carpenters Pincers? like wire cutters or long nose pliers type of thing? so do they just pop?

 

Like these..

 

These types of fixings will either screw in (like a plastic self-tapper), or push-in (possibly with a sliding rod in the hole, which when depressed, locks it in place).

Try first to turn it, if it doesn't rotate (or it doesn't feel like it screws into place), then I would carefully attempt to lever it out using a thin screwdriver in the hole, and a large flat-headed screwdriver under the collar.

Don't attempt to push the plastic rod through, or you will lose it, and the fixing will not seat tightly without it.

Once you have retrieved the entire fixing out, the plastic rod can be pushed back, allowing the fixing to be re-used.

I have to do this regularly, on all sorts of cars (which each have their own method) - I don't carry spare clips, so I need to re-use what's already on the car.

What I have outlined is how I would approach this.

HTH

Paul