I mostly use apktool because its really simple and works most of the times. You can visit this link
http://code.google.com/p/android-apktool/ and download the
apktool-install-windows-r04-brut1.tar.bz2 and
apktool1.4.3.tar.bz2 files or directly download the files needed for the apktool to work from the attached rar that i uploaded. Now unrar the archives if you downloaded from the link or if you downloaded my apktool.rar, unrar it and create a folder in your C:\ drive called apktool or in any other place in your drive but i suggest in C:\ you'll see why. Now in this folder place the three files that you extracted but also,
place the framework-res.apk and framework-miui-res.apk. Open up the command prompt and navigate to the folder that you placed all these files if you did like i said in C:\ just type in the command prompt
cd C:\apktool where apktool is the folder with your files in. Now type
apktool if framework-res.apk and hit enter and do the same for the
framework-miui-res.apk. You will get something like framework-res.apk installed on location blablabla. If you dont get this message you did something wrong, post here to help you. Now to
DECOMPILE an apk just type
apktool d framework-res.apk and hit enter.
d stands for decompile. Now a folder named framework-res will be created with all the smali and xml files you want to edit
To build back your apk just type
apktool b framework-res .
BUT REMEMBER you have navigate to the folder where you placed the files of the apktool, for the apktool to work.