Carefully peel up the antenna flexi.

This end of the cover has a tab that slides under the other part of the body, preventing vertical movement.

These tabs poke downwards, preventing horizontal movement.

The end cap belongs to this cover, but there is a peg on the main body poking through, also preventing vertical movement.

So there's no good way to do this. I pried up in the middle (watch out for the electronics underneath) until the orange tab popped out. The whole piece then slid off.

To reinstall, I inserted the orange tab, then pressed the rest down, deforming it til the green endcap snapped over the peg. Nothing broke, but it's a little scary.