I agree with the others who said training to ring the bell is quite easy. Jessie Joy learned very fast at a very young age. We have a jingle bell on a long cord and hung it from the door knob. We rang it at first, everytime we took her out, and before long she was "slapping" it with her paw.
She still rings to go out now, and Simon comes running in the room to see if we are going to let her go or not LOL. He doesn't want to ring it - no need, she rings it for both of them.
A dog is the only thing on earth that loves you more than he loves himself.