Many people who use custom themes or launchers are familiar with WidgetLocker. What many people don't realize, though, is that customizing WidgetLocker itself is a fairly straightforward task. Better still, there are plenty of existing customizations available, meaning that you have to do little more than shove your modified .PNG files into the APK.
Before / After
Dalton Gore - better known as @colormeandroid - is responsible for gathering the individual mods and creating the guide. While the guide is a little too light on details for newbies, it does provide the luxury of choices - he provides instructions for 5 methods:
How to apply the images:
Personally I recommend using APKManager!
1) Using APKManager - Sign the file and install it using a File Manager
2) Using ADB - If you are unfamiliar with ADB there's a step by step guide
3) Using Root Explorer - It's a paid app and ROOT is needed
4) Using NinjaMorph - Get it at the Market. Requires S-OFF
5) Alternative method - When ADB won't work properly you can try this.
I first tried using ADB, but found I couldn't reinstall WidgetLocker. After screwing around for an hour without succeeding, I tried APKManager, only to encounter the same issue. Turns out that after you modify the APK, you need to uninstall WL and reinstall with the new APK. In hindsight, I feel like a moron. Even with my limited ADB and modding experience, if I had known this going in, it would have only taken about 10 minutes from start to finish.
Another tip: if you're using the ADB method, you should open the APK with WinRAR or 7zip (I used WinRAR). You're told to replace the PNGs, with no detail on how to do so inside an APK. Turns out it's the simplest way imaginable: no unzipping necessary - just open the APK in WinRAR and copy and paste (overwrite) to the appropriate folder in the APK. Then click OK and close out.
I promise you, the task is not nearly so daunting as it looks (I avoided testing it out for over a month because I thought it would be more difficult and time consuming than it turned out to be). If you take the dive, feel free to post your experience and advice below - and don't forget to include a screenshot!