If you see your neighbor pointing a camcorder or camera
at you, then assume that you are headed to federal court
and he gets the "finders fee" for turning you in.
Seriously, you don't need a license, but you are in violation
of federal law (felony) if you don't properly recovery the
refrigerant. Any vacuum pump and an empty freon tank
should work adequately, but if you are asking these
questions, then you probably don't have the equipment
or expertise to do the job correctly.