Sometimes a web host will give you the ability to adjust the permissions on your files and folders from your Account Manager. However, I don't think Bravenet's editors allow that. The simplest method is to us a FTP tool that includes this ability. If you don't already have one, a good free FTP tool named Filezilla can be downloaded.
When you connect to your web site with FileZilla, it will display the permissions for all of your files and folders. If you select a file/folder, and use your right mouse button, you can select "file attributes". This will pop up a "Change File Attributes" window where you can make the adjustments necessary.
Opening up the permissions on a file or folder is usually only done for configuration purposes. Make sure you reset them when you are done with the configuration.
