After watching non-mercedes dealer change my oil and paying a substantial amount; have decided to change oil myself in the future!! My questions are: Does the suction of oil from crankcase have any downside vice taking out drain plus; and what kind of tool(s) do I need to unscrew oil filter cap and filter?? Is anything associated with an oil change that require a torque wrench...and finally where can I purchase items needed to manually change my oil?