I'll be swapping out the chrome intake bezels (a.k.a fangs) from the lower part of our 2012+ bumpers for the black ones. Question is, how do they come off? Does the entire bumper need to come off?

It's this part for reference:
https://parts.jaguarpalmbeach.com/p/.../C2P22649.html

 

My 2010 'Gills' just popped out. They have holding hooks molded as part of them. Snap back in place.
Not sure if your 2012 is the same....