Changing Servers on Existing Thunderbird Account

I have two accounts on my Thunderbird mail client. On one of them I changed my email hosting from GoDaddy to Gmail. I hate Gmail's mail client interface so I want to keep everything on Thunderbird. I entered the new Gmail server info but the account cannot access the Gmail server. It's probably a password issue, but it never asked me for the new Gmail server password. The Gmail servers do not show up on the list of servers on the Passwords page, so I can't change or add any passwords. I don't want to set up another new account because I need to keep all my previous mails, settings, etc. in place.

So how do I just change the servers (in and out) on an existing Thunderbird mail account? TIA.