How to clear single sign on credentials

Hi,
We have a user setup to access Nav using click once using their Office 365 single sign on.
We want to change the user that logs in but when we run the Nav client it now does not display the login page & uses the cached single sign on credentials.
Other than using a new windows login, can the cached login be deleted so the user is prompted for their login details again so they can enter a different login?