Well i'm not on my laptop with the software to step you through it exactly, but Go here
FileZilla - Client Download
and download filezilla and install it.
Then open up filezilla, go to File, then like site manager, something like that. Then a window should pop up asking you information, type in the ip address of your iphone in "host", the user should be "root" and password "alpine". Make sure the servertype is SFTP - SSH File Transfer Protocol. Try leaving the port blank, but if not put 21 if it doesn't connect on the first try. Go ahead and click connect and it should load up the root directory of your iphone, and then you can proceed to do what i told you to do in my previous post.
If you don't know how to get the ip address of your iphone, you need to go to the settings app and look in the wireless tab. I hope this helps, good luck!