Yes, both AVG and avast have uninstall tool, they can help in case you get problem during uninstall.
AVG: http://www.omidfarhang.com/computer/how-to/uninstall/security/avg
avast: http://www.omidfarhang.com/computer/how-to/uninstall/security/avast
even more: http://www.omidfarhang.com/computer/how-to/uninstall/security

If you need any more help I will be glad to help so. :slight_smile: