well first u have to extract the file. right click it and find extract file. just hit next and what not. download winscp. it ssh's into the the iphone's root files.
WinSCP :: Free SFTP and FTP client for Windows .....thats the link right there. just hit download. once u have downloaded it. launch it the program. it will now ask u for the host name. type in ur iphone's ip address. you can find it in setting. wifi. hit the blue arrow to the right of ur networks name. it should be 192.168...... for the user name, type in root. for the password, type in alpine. once u have done this it should go into the iphone's files. if it does not work, u have to go to cydia and download openssh. after u download that, winscp wont recognize the first few trys, but keep trying at it will. u will see the drop down bar. it should say root. click the drop down bar and click / <root>. click the folder library, than themes, and add the theme there.