Installing iPhone themes in *.deb format

First Download an SSH Client such as Cyberduck for OSX or iPhoneTunnel if your on Windows.

• SSH into your iPhone  
• Go to /var/root/Media/Cydia/AutoInstall 
• Copy the *.deb file there and that just reboot your device(if Autoinstall folder is not lying in /var/root/Media/Cydia then you can create yourself).
•  Or if you have ifile (follow the link if you dont), you can ssh into your iphone and put it anywhere you like it. 
• Open iFile in your iphone and look for your deb file, tap on it and click install. You just need to respring in order to have your theme installed.