Here are the current steps you need to follow in order for a user to clear their password/userid from the outlook plugin memory cache: 

(1) Under Fuze Meeting Account tab, press the Login Info option.

(2) In the new window which pops up,  press the "advanced" button.

(3) To the Fuze Meeting Url value append "1" and press OK.

(4) Now press the "Advanced" button again and delete the "1" you appended, so that the URL is back to its original form.

(5) Now you can change your userid/ password.

We are currently working on a 'Clear Credentials' button in the near future so you may login as a different user, or put in a new password.  Thanks!