All my instructions are going to be for GNU/Linux. I use ubuntu in particular, so a lot of my instructions will be customized for Ubuntu, although it should be possible from any GNU/Linux distribution, Mac OSX, and even windows also.
The ABSOLUTE very first step should be grabbing the android SDK. This can be done by going to the website: http://developer.android.com/sdk/index.html
and downloading your operating system's version, I'll assume we're running linux again.
tar zvxf android-sdk_r06-linux_86.tgz
Then we need to make a bin directory in our home since this is where we'll be placing all tools.
Now you'll need to add this bin directory to your PATH.
In my ~/.bashrc I have at the very bottom
I have the same in my ~/.bash_profile and ~/.bash_login but I'm not quite sure what all is neccessary.
Then you'll need to grab apktool and aapt like so:
tar jvxf apktool-1.3.1.tar.bz2
tar jvxf apktool-install-linux-2.2_r01-1.tar.bz2
You should now have apk installed!
Type the following at a newly created console window:
If both of those do not give you detailed help, you did something wrong.