Retraining question...

[RigaMortus2]

From page 28 of the PHB, under Retraining.

Every time you gain a level, you can retrain your character: change one feat, power, or skill selection you made previously. You can make only one change at each level. When your class table tells you to replace a power you know with a different power of a higher level, that doesn’t count as retraining—you can still retrain an additional feat, power, or skill as normal.

Where can I find my "class table", and where does it tell me when I can replace a power I know with a different one?

 

[Calidarien]

I believe they are referring to the table on PHB p.29, although I'm not sure why they said "your" given that all the classes share the same table, at least presently. Perhaps that will not be the case in the future. Anyway, at appropriate levels (e.g. 13th, 15th, and so on), the table states what powers are replaced. Incidentally, all such levels are marked with an asterisk on one of the numbers in the rightmost column ("Total Powers Known").