There are two T8 screws hidden under this strap hole at the top of the radio.

Use a thin tool, like a spudger or pick to gently pry this cover off and set it aside.

There may be some adhesive to hold this cover on and it may be tricky to get a spudger in. You may find it easier to use an inexpensive or disposable size 1 flathead to pop this part off.