update members set warn_level = 0, lastwarn = 0 if you have a prefix like ibf_ put it in front of the members in the command like ibf_members . Be safe and export the members table form acp > sql toolbox or phpmyadmin before running the command.
Request free invision power board files below, and i'll get it for you and upload here, give it 24 hours of course for the mods / admins to approve. ! Start requesting ;p