How to remove Avast Anti-Theft on Android after factory reset?

Hello.

I want to sell my old phone and in order to remove everything from it I did a factory reset.
But after I’ve changed the SIM card, I got a notification on my other phone number that the SIM is changed, so the Anti-Theft is functional.

How to remove it from my old phone after the Factory reset? Please help.

Thank you.
Regards

Sorry, I’ve answered you there http://forum.avast.com/index.php?topic=111176.msg873952#msg873952

does this help? http://forum.avast.com/index.php?topic=111215.0