[EVO 4G Themes and Apps] nukedukem:
This is a very basic guide to beginning themeing. It is not meant to be all-inclusive, just some simple steps that can be taken to make your own custom theme fairly easily. This guide should allow anyone to be able to grab images they like from any ROM and incorporate them into their own.

I SUGGEST YOU ALWAYS MAKE A BACKUP OF ANY FILE BEFORE YOU THEME IT AND NANDROID FIRST BEFORE FLASHING

Here is a basic overview of changing images in an apk:

1. Get your base file to theme – framework-res.apk, com.htc.resources.apk, phone.apk ect.

2. “Open” apk archive with 7-zip (don’t unzip!) and drag and drop the new images into the appropriate folder.

3. Flash new file.

Now some details:

1. The first step is to obtain the file you are going to theme. The file you are themeing ( i.e. going to flash to your phone) must come from the ROM you are currently running. Always use files from your current ROM as a base, however the images you want to change can come from other ROMs, or you can edit existing ones or make your own from scratch. You can obtain your theme base through an ADB pull of the files from your phone, or simply downloading the ROM zip file and extracting the files you need.

2. Now that you have the file to theme, don’t touch it! OK, more specifically, you won’t unzip or do anything to this file except “open” it with 7-zip (unless this is a market app, but more on that later). You are going to drag and drop the new icons into this file by “opening” it and navigating to the appropriate folder. The images you want to change are stored in the apk under /res/drawable-hdpi. Once you have your new icons from other sources, open your base file and navigate to this folder and drop them in.

3. Now you can flash this new file. I have provided empty zip files that you can place your themed files into and flash in recovery. Place your framework-res.apk and/or com.htc.resources.apk into the /system/framework folder located in the zip file provided. Now highlight the META-INF and system folders and zip them up. You can now place this file on the root of your SD card and flash. System apps can be placed under /system/app in the zip file.

Some more info on common themeable files:

Framework-res.apk – this is the meat and potatoes of a theme. On an AOSP ROM it will contain almost everything you want to theme aside from individual apps themselves. Sense ROMs have another file com.htc.resources.apk, as well as framework-res.apk. Both of these files are located in a ROM under /system/framework.

System apps: These apps come packaged in a ROM under /system/apps. They can be themed in the same manner as a framework apk. Some of these apps include Gmail, browser, camera, ect. Place them in your flashable zip under the folder /system/app.

Market apps: These apps are downloaded from the market and are can be pulled from your phone from /data/app. These files require a bit more to theme. They don’t share the same signature as the system apps and you must resign them using a program such as apkmanger. Place them in your flashable zip under /data/app.

If there are any errors, or if anyone has suggestions please let me know. I may have over looked some details, ect.

Thanks to everyone on XDA who has shared their knowledge and made this a great community!