I did this to my Cayenne , removing side badges only .....
They are stick on , quite well stuck on but use the following method :
1. Soak a piece of cotton wool long enough to cover the badge with a tar remover such as Autoglym or 'Autosmart tardis.place on the badge and leave to saturate in behind the badge.
2. Remove cotton wool
3. Using a 200mm piece of fishing line gently 'floss' behind the badge from left to right ( or opposite ) until it is easily removed.
4. The badge adhesive will have left a residue behind which might show the 'diesel' image on the panel.
5. Clean the residue off with tar remover until all removed.
6.Polish the area / panel until gleaming .
Job done .......and much cleaner lines afterwards
Terry