Manage SQL creds in Excel

When creating a database connection using excel to a SQL server which has previously been connected to Excel keeps trying to use some old credentials and won't ask me for new ones. Where can I managed these credentials so that I can flush the old creds and input new ones. The old creds never worked so a connection object doesn't exist for this database but these creds seem to be cahced and upon failure to connect the only options I get are retry, cancel or edit but edit doesn't let me do anything with the way I'm authenticating.