The plastic cover has retaining tabs on its bottom -- see the third picture.

Starting on the right side of the display, slide the antenna's plastic cover approximately 1/4" to the right.

Then, lift up the right edge of the plastic cover just enough to separate it from the display.

Continue lifting the cover along its length, until the entire cover is separated.

Remove the plastic cover and retain for reassembly.

When putting back the cover, follow the instructions in reverse -- put it into its channel about 1/4" to the right of where it should normally reside, then slide it into its location.