Palm Pre Plus - Manual (Page 167)

Chapter 11 : Troubleshooting 167
4 Press and release the back cover release .
5 Slide your thumbnail or a credit card into the hairline opening between
the back cover and the phone, starting at the bottom and moving
halfway up one side until you hear the clasp (x) release.
6 Repeat step 5 to release the clasp (y) on the other side of the phone.
7 Lift off the back cover.
I can’t get the back cover back on
1 Position the back cover over the phone and gently press the top two
clasps (a), located at the top corners. Then press the two clasps (b)
halfway down either side of the phone.