Sorry Kev...once they get pushed off the page, the only way to change them ...is to hack your game....
But...It is
Your game...and their
is a link for an editor, somewhere these posts.
Other than that....the only thing to do is
not to let that happen..after my first game..I was very cautious about the skills I learned, just so they were still available..I made it a point to get them maxed out, before they got pushed off.