To accomplish this manipulation, there are many methods and has been for Windows or Mac OSX. Not too much like hitting dozens of command lines, I fell back on a method that works only from Windows, but has the huge advantage of being extremely simple and fast (twenty minutes).
I offer the following translation of the original guide and a supplement on installing applications from the iPhone.
The various steps in the sequel.
I am not responsible for any problems you may encounter, this guide worked perfectly in my case, but we do not guarantee any results at home. You try these manipulations and knowing you'll pay the consequences if there were any problems
Install the latest version of iTunes on your computer
For information, I used a machine with Windows XP, but it seems that this guide also works for Windows Vista.