While Perl allows for more than one way, there are some ways that are clearly not as good as others :-).

Certainly re-blessing into a class that has imported the appropriate roles is better than manually trying to remove roles from a class. I think much of the functionality of roles is implemented by manually importing the appropriate subroutines in the package namespace, instead of using the @ISA mechanism in the hope of getting the correct implementation of a method. This makes "unimporting" a role quite hard to do.