Open iTunes and create a new playlist by clicking "File" and selecting "New Playlist." The new playlist will appear in a column on the left side of iTunes. By default, it will be labeled "Untitled Playlist."
Rename the playlist by highlighting the playlist and then clicking the playlist name to edit it.
Drag the copy protected MP4 files into the playlist you created.
Click on the playlist to highlight it and then click "Burn Disc."
Click "Burn" to confirm this action.
Insert a blank CD-R into your computer and iTunes will burn the copy protected MP4 files to the CD.
Open iTunes preferences and then click the "General" tab.
Click "Import Settings."
Choose an audio encoder from this menu to convert the MP4 file to, such as WAV, AIFF or MP3.
Click "OK" to confirm this choice and then click "OK" to exit this menu.
Eject the CD and then insert it back into your computer. After a moment, iTunes will prompt you asking if you'd like to import the CD.
Click "Yes" and the copy protected MP4 files will be ripped from the CD and converted to the format you chose from the "Import Settings" menu. You have now successfully removed copy protection from an MP4.