Please, for the sake of yourself and goodness, read this post on how to manage your themes properly.
Most of your questions can be answered even before you ask them by simply following this short tutorial.
To change your themes, you need to have jailbroken iPhone. It doesn’t matter if its 1st generation or 3G. Jailbraking your phone will allow you to install third party applications which will allow you to install and change your themes. If you haven’t done it yet, i have simple tutorial on how to do that - here. (Just in case you ask, it is safe and you can put your phone back to normal if you want.)
Second thing to do, would be installing WinterBoard from Cydia. Just open Cydia, choose ‘Search’ option on the bottom right corner and type ‘WinterBoard’. Install it. After successful installation, WinterBoard will create specific folder where all of your themes are going to be installed/located.
You also need to configure your FTP client if you haven’t done it yet, click here.
- Download any theme(s) you like
- Extract zip file with Archive Utility if you are on the Mac, or by right clicking on the zip file and choosing ‘Extract all…’ on Windows.
- Drag and drop extracted theme(s) folder into ‘/Library/Themes’ using your favorite FTP client.
- Open WinterBoard on your iPhone and tap on the theme you want to apply
- If you want to change you ‘lock background’ to reflect your current theme, take a screen shot of your theme and set it to be your wallpaper
- Click here for theme selection...