To remove the DRM from a Kindle, you will need the following: Kindle for PC software program and Python scripting program.
Install your Kindle for PC software, if you don't already have it. You can get it from Amazon. You will have to register it to your account. Close it. Install Python at Python version 2.6.4. Download Python. Download the scripts, available at Iheartcabbages. Click and drag the Unswindle onto the Python.
Select and open the book that you want to use. The Python script will ask you where you want to save the unencrypted file. Now, you have a portable one. You will be able to share your books with your friends. This will not work with Topaz.