Looked and might have overlooked this somewhere. And I get that the career feeling is more of an overall feeling of the default mode for the character (referencing Han Solo and his default outlook). I get it, but there are a lot of things that have come out since the beginning (not that I or any of my players can really claim that as the reason, but we certainly have not had all the books).
Is there a system in place so that someone could change careers at some point? Obviously, there would need to be limits, because if you could do it willy nilly it would make buying talent trees easier. But if a character has really thought about it and now has shed his smuggler past and is embracing his role in the Rebellion or as a Jedi, can a character change careers?
If there is nothing officially, how do you handle it? Do you take away career dots and add new ones without removing training or giving any benefit? Do you strip them of some of the things they have learned to do previously because they have not been practicing it and have lost it? Do you handle it all through story and just have them create a new character sheet?