So far as I know, there's no way in the game to swap out a PP power for something else.
The Reserve Maneuver feat might work. The wording is a little unclear, so there's some debate.
You can only swap a power that has another legal option for that power's place. PP powers only have one option, so you cannot swap.
Sounds about right to me, but what about the Adroit Explorer?
Adroit Explorer doesn't have any powers, only features.
Those features select class powers, which can be retreained.