Pull the plug, then go inside and have a beer or two while it drains, hot or cold.
And if you dont mind wasting a quart or so, I recommend dumping at least a quart into the oil fill while the plug is out...will help to get some more of the gunk out.
The irony about quick oil change shops is they have great prices (as compared to a dealership anyway) on pretty much all their services EXCEPT the basic oil change...that IS a rip-off lol