You can change your own directory permissions using the file manager.  Find and choose the file you wish to change permissions for using the file manager in your control panel. Select/highlight the file and use the "Change Permissions" option at the top of the file manager.

Please ensure that files/directories never have 777 as it may result in an Internal Server Error. Please ensure that all PHP files and directories have 755 permissions.

Changing permissions can also be done through an FTP client or SSH command line.