To reset Canon printer to its factory settings, first, make sure the printer is turned on. Navigate to the printer's settings or setup menu using the buttons on the printer's control panel or the touch screen. Select 'Device settings' or 'System settings' and then select 'Reset settings'. Confirm your selection by selecting 'Yes'. The printer will then reset to its factory settings. Please note that this will erase all your customized settings and you will need to reconfigure your printer.