How can I change permissions of the file bridge.php (chmod 666)?

To set the correct permission (chmod 666) to the file bridge.php you need to connect to your server through FTP application, for example Filezilla. Then, find bridge.php in the directory bridge2cart and click the right button of your mouse on it.

From the menu choose “File permissions..”.

After that write 666 or check boxes near Read/Write.