I understand that if I need to use avast virus cleaner free, the resident protection must be off, is anybody knows how to do that? I have the version 4.8, thanks.
No.
The avast virus cleaner is incorporated into the avast program, so you shouldn’t need to run it as standalone. If a virus/worm infection was detected that could be cleaned it is my believe that it would be launched by avast. Not to mention the avast virus cleaner is only designed to cleane a specific limited list of virus/worm infections (that list would have been displayed in the page where you would download the avast virus cleaner).
Why do you feel you need to run the cleaner ?