Need to reset connection

Originally I used a GOOGLE WORKSPACE GROUP for the sender of emails and created the OAUTH credentials using my own email address. This had not worked well, as I continually get copied on all the email messages sent by the server.

I created new credentials, but my staging and production sites remain in the connected state, so I cannot test the new OAUTH.

Wondering how to reset the connection so I can test in STAGING, without affecting PRODUCTION.

Thanks,
Daryl