You can't. Sorry. This topic has been covered ad nauseum by a slew of people on a number of forums. A few charlatans have professed that they have done it, but no repeatable method has proven to work.
So, for right now renaming your account is not possible. Hopefully EA will fix this in the future -- maybe in a later patch.
So, for right now renaming your account is not possible. Hopefully EA will fix this in the future -- maybe in a later patch.