These files are available in OsCommerce admin panel under Tools -> Define languages. You can also use FTP or File manager in your hosting cPanel to edit these files;
1. Log into your OsCommerce admin panel and navigate to Tools -> Define languages:
2. Choose language from the drop down (English,Spanish,German or Russian):
To edit Conditions of use page, you should edit conditions.php file. To edit Shipping & Returns page you should edit shipping.php file;
4. Open the necessary file, make changes to the text and save changes.
5. If you have several languages on your site, you should edit the corresponding files from each language folder.
Feel free to check the detailed video tutorial below: