You can either go to the settings and select the reset option which will bring back your printer to the factory settings or use a reset button. Now, if you are wondering where is the reset button on a Canon printer.There is no reset button on a printer which is labelled as reset but you can reset the printer using button rather than navigating the settings. Hold down the stop button and the power button at the same time. Now, you have to press the stop button five times. This will reset your printer back to factory settings. 

https://connectmyprinter.com/how-to-reset-canon-printer/