I do not get why folks want to do a topside oil change it is not that hard doing it the old fashion way, and personally I feel you can not get as much sludge out top side.
On my MLs yes you must remove the guard pan if still there not a big deal plus you have the added benefit of doing a good visual inspection of hoses and bushing. If I had done a top side oil change on our 350 I would of never found the broken shock bolt 3 weeks ago. We did not notice any ride issue, went to pull the oil plug and "Oh the passenger shock is not attached, what do you know"?
Ok aside from 6 fastners holding on the pan, you have the mess of the oil spilling all over the suspension. Get a foot long piece of 4" Aluminum drier vent pipe ( this is your new Mercedes Benz special tool. Loosen the plug, with the vent pipe split open fit the split c shaped between the top and bottom of the plug. it is aluminum you can bend it to fit any way you want . But slope it towards the front of the car. stick your hand up it undo the plug the last turn or so and you have a spillway directing the oil into you 2 gal plus oil pan.
While it drains take you flashlight and have a good look around look for leaks, at hoses, bushings, motor mounts if you can. Prevention is worth a lot, sorry I do not get doing it the quick way, otherwise I'd take it to JiffyLube. Most people that do their own oil change do it not to save money but because then care about their car/s.
Change the oil on a Bugatti Veyron then you have something to complain about it takes about 2 days.