If you think this is to easy to be true then your right.
Step 1 -
Make sure you have a xbox360 transfer kit for you hard drive you can use but that takes too long...... Plug Your "20-120"GB hard drive in to your computer and open up "If you havent got any of these apps then they will be at bottom of the thread" Then watch my youtube video of how to put them on........ just watch me take them off but what you need to do is do what im doing but put the files where im putting them =D
In this post the files are ................ winRAR ................