Bezels always (in my experience) are simply clipped in by their plastic wedge shaped tags.
First you need the drawer open, and you then remove the drawer front - which also just clips on.
Then press in the bezel retaining tags one at a time, and ease off the bezel.
The fit the new ones.
You'll need the drive out of the case (or at least slid forward enough to show the retaining tags - say a couple of inches).
It's very simple in practice.