I have auto renewal for Avast Premier coming up and it says for 3 pc’s. I only have 2 pc’s, desktop and laptop. How can I change it to 2 pc’s? I have Premier on desktop and Internet Security on laptop. Is the price different for just 2 instead of 3 pc’s? How can I change this?!!
You can’t unless you take two licenses, one for each system.
I have to update my credit card info also. So, do I cancel my auto renewal and start over by purchasing one premier for desktop and one internet security for laptop? It says if you don’t use auto renewal you don’t get the better price as a valued customer or something.
Often with the auto-renewal you pay more than taking a new subscription.
How to cancel the auto-renewal, change credit card details (and other billing issues/questions) see > https://www.avast.com/faq.php?article=AVKB24
What license(s) you should take is entirely up to you to decide.
Ask yourself the question if you need/want the extra’s for a paid version.
https://www.avast.com/compare-antivirus
Thank you Eddy!! 
You’re welcome.