How to install iPhone themes from PC, to iPhone?

Sorry, I'm new to jailbroken stuff!
My iPhone 4 is Jailbroken. I downloaded/saved and extracted this theme; http://www.mbtheme.com/Iphone_theme/Rilakkuma_84976.html
I'm looking up tutorials, and they say to get 'BSD subsystem' from 'installer' which is downloaded when you download 'Jailbreak.me' … Well i downloaded Jailbreak.me, it didn't come with 'Installer' and I can't find it in Cydia.
To be specific, this is the tutorial i found:
3. Now if you still want to move them from your computer to your iphone, see below.

4.install BSD subsystem (from list of apps available from Installer)

5.install OpenSSH. Once installed and having access to your Wi-Fi get your iphones IP address from Settings->Wi-Fi->click the arrow next to the Wi-Fi network you are connected to.you'll then see your IP address.

6. SSH into your phone.ssh -l root 10.x.x.x (use your ip address). If using a mac just use the Terminal app to ssh. If windows, i don't know find a terminal type app to command line to use ssh.

7. Use password "dottie" or "alpine" when asked after ssh'ing into your phone.

8. Get a SFTP program to transfer files to your iphone from your computer.server will be your IP address of your iphone, user = root, password = dottie or alpine.

9. Summerboard themes are in Library/SummerBoard/Themes/, this is the directory you'll place your themes.each theme should have it's own folder.

Don't bother using your computer. Just go into cydia, search for a theme and download it to winter board (summer board in your case), open your summer board and select the theme you want to use!
hope it helps