How to disable an enterprise password?

I gave my mother-in-law my old company blackberry. She is using the phone and SMS parts of the phone, no problem, but can't set up email or anything because she is being asked for an enterprise password. I'm guessing this was set up by my old company. How can I instruct my mother-in-law to disable the need for this enterprise password?

It may require a security wipe if you are no longer affiliated with the issuing company.

Posted via CB10

She will also need to have an active BIS service to have anything other than the BES activation in the Mail setup options.