How do I add my Comcast email account to Thunderbird?

How do I add my Comcast email account to Thunderbird now that it has switched to Yahoo? When I try to add it all I get are the Comcast mail servers in the setup program to add an email. When I try to edit it and change it to the Yahoo mail servers it does not work. I have used Thunderbird for many years and Firefox for a browser. When I started on the internet I Used Netscape. Firefox and Thunderbird were started by Netscape programmers if I remember right. I love both Thunderbird and Firefox and don't want to change but the way it is now I cannot use Thunderbird for email. I have tried both Pop3 and Imap setups. Neither will either allow me to set up my email in Thunderbird to get email from Yahoo. I do not like the Yahoo Website for email.