I'll assume that you're talking about Class::MethodMaker
. MethodMaker defines its methods on-the-fly when the class loads. When you ask "where do they put the accessors?", do you mean "where is the accessor implementation written out to a file?"? If that's what you mean, the accessor implementation isn't written out to a file-- it's just evaluated at compile-time.
To modify these methods, you just need to define your own. To quote from the perldoc:
To override any generated methods, it is sufficient to ensure that the
overriding method is defined when Class::MethodMaker is called. Note
that the use keyword introduces a BEGIN block, so you may need to
define (or at least declare) your overriding method in a BEGIN block.