root folder of your wordpress instalation and the path i mentioned above . Either via FTP or your Hosting Controll Panel.
At the end of 04 footer.php.
You should know what you do, else your site could be shown incorrectly or maybe nothing.
IF you dont understand what you read , please dont try to change something at these files.
But you can easily remove the whole copyright section under the footer via css – there is also a topic here.
