[忍]

Am I going crazy or do I remember that adepts can "forget" powers to learn new ones? I can't find it in any books, but it seems like something Ive read.

[firebug]

I don't recall anything like that.  No one else has anything like that either (no unlearning skills, or swapping qualities, or trading in spells known) so I'd be inclined to assume it's not possible.  Though I'm sure many GMs would allow a retroactive change if a power was picked without realizing some significant flaw about it, or if it went totally unused and was just a waste of points.

Maybe you got it confused with another tabletop RPG you play?

[Kiirnodel]

There is however, an adept metamagic that let's you temporarily transfer power points from one power to boost another.

Away from books at the moment, but pretty sure it's in Street Grimoire.