[3.5] Alternate Class Features after Creation?

[Frission]

I'm new to the whole concept of alternate class features for characters, so I wanted to ask: Can an existing character gain/retrain-for an alternate class feature after char creation? Like a rogue dropping trap sense for penetrating strike?

[Yael]

In the player's handbook 2 there is a class feature retrain section with its cost and time for it.

Edit
It's on page 192, though it works for multiple-choice class features. Maybe you could go into the Gate of Dawn or the Necrotic Craddle to make the changes, though you could always ask your DM to allow Class Feature retrain to work in the one you need.