Usually a plug on bottom of sump. But you could get a pump system, stick the pipe down the oil level hole, and suck it out. Not as good, So undo sump plug, with a container below. let oil drain out. PUT drain plug back in, refill with correct grade oil. Done.
You may need to remove under engine covers, probably 1/2 turn locks, but not every time. But whatever they are, just undo them, remove cover. Then as above, the refit cover. Easy. That will be £100 thanks.
SD, January 2012