You can do anything you want to short of profiting off of your altered unlicensed work.
If I buy the Mona Lisa, change the picture slightly, then sell copies of my portrait, do the former owners have legal recourse? The problem is, those that make movies want to control the path of their art forever. It is what makes them rich, but it is a system that is both wrong, and archaic. They made their money when they sold the rights to movie houses, DVD makers and to me. If I want to alter and re-sell, why should they get to say anything?