Editing your permissions is as easy as accessing your cPanel, this you can either do from your ClientZone, followed by selecting the Hosting tab, followed by choosing your Domain and then choosing to access the cPanel.
Alternatively you can access your cPanel by entering your domain name in your web browser followed by :2082
You can will then just need to enter your cPanel details which will also be the same are your FTP details.
Once in the cPanel, you will just need to find the File Manager, and after opening it, you will be presented with your full site and hosting map, you just need to browse to the files or folders you want to update the permissions for. You can update the permissions by right-clicking on the file or folder and then the Permission option from that list.