Hi - if it is the carpet clip as shown in this very poor picture you just lift carpet over it.
You may notice I only have 1 clip = that is because my car was delivered via transporter to my house and the clip was broken when I got car. Talking to local dealer they think the whole base carpet has to come out to fix it as clip is hard fixed from under the base carpet (instead of screw fit from above) - I am waiting for dealer who supplied the car to advise how they are going to get this fixed - so be careful and don't break these flimsy clips!!
I have settled for standard mats on the basis of experience with so called luxury mats on XF but given bwd post I as above?am wondering whether the standard mats are fitted as above. Information please.