What I did (and it works great) is... I used a plastic drum (you can usually get them from a car wash) cut the top out leaving the lip. Then I made a lid out of plywood thats about two inches wider than the drum, cut it in half used a piano hinge all the way across the top with with a strip of an old inner tube under the hinge as a water proof gasket and sealed it with deck sealer. Then glued three 1"x1"x2" blocks evenly around the underside of the half that doesn't open and used 1-1/2" screws to screw through the blocks into the top lip to secure it.
That way when they dump the oil in all they have to do is flip open the one half and dump it in. I just asked them to keep the lid closed when they're done.
(The easier you make it for them the better chance you have of getting the oil).
To remove the oil I use a 2" gas pump bushed down for a 1" hose It will even pump the thick cold oil in the winter. No fuss no mess just throw the suction hose in and start the pump. I pump into a tank in the back of the Powerstroke.