Hi everybody.
Today I realized that I have to renew one of my licenses.
When I display the list of them, I figured out that there is a license that has “auto-renewal subscription” and I want to change that, I don’t want it to be auto-renewal.
Can I change that?
Hi and welcome. 
You could try either of these links
Find My Order> Cancel Auto Renewal
https://www.avast.com/find-order
OR
Disabling Automatic Renewal service for Avast orders distributed by Nexway
https://www.avast.com/en-us/faq.php?article=AVKB136#artTitle
Disabling Automatic Renewal service for Avast orders distributed by Digital River
https://www.avast.com/en-us/faq.php?article=AVKB126#artTitle
Stopping Auto-renewal is impossible!
I have spent a couple of hours trying to cancel Avast auto-renewal. I have followed all the steps on Digital River and tried to find someplace on Avast home. I am unable to cancel my auto-renewal which was supposed to be easy. There is simply no way it can be cancelled.
I have all the paperwork including my Order I.D., Order number, passwords. None of the information sent to me when I first subscribed is now correct. Have I been duped?
The links in the post above yours have certainly worked for others in the past.
If your transaction was handled by Digital River that should have produced options, but of course if it wasn’t digital river it won’t.
Generally I find starting with the find order link is better as I don’t believe it matters who handled the transaction.
You could try submitting a support ticket and see it can be cancelled that way.
https://support.avast.com/support/tickets/new.
I needed help, but it is solved itself, thanks.
https://www.avast.com/faq.php?article=AVKB126
If for whatever reason that isn’t working, submit a ticket (as has been explained many times).