Using the flat end of the spudger, very carefully lift up the corners of the white plastic piece. Do not disconnect the two.

With the help of tweezers (needle nose works best), pull the connected plastic pieces out.

If the two plastic pieces come apart refer to the last picture, showing the orientation in which they should be connected.

For reinstallation of the plastic piece use tweezers to put it back in place and pop the bottom half in before the top.