Obtain an FTP client. Use FileZilla on Windows, and Cyberduck or Transmit on Mac.

Connect to your Yakkel account via FTP. Your username and password is the same as your Yakkel password.

Once connected, right click on the folder or file you want to the change the permissions on. Click "File Attributes" in Filezilla, or "Get Info" on the Mac clients.

If you know how to use CHMOD numbers, you can enter the appropriate number in the permissions box. If not, just check the boxes for the certain permissions your want. BE CAREFUL how you change the permissions so that everyone can not edit or execute the file. In general you want to keep the "public" or "world" permissions as read-only.

If you want to change ALL files within a folder, click the "recursive" check box. This will go through and change the permissions of the folders within the one you are changing.