This step is only necessary if you wish to flush all of the old oil from your engine. You may consider doing this if it has been an especially long time since your last oil change or if some foreign liquid has been poured into the filler hole.

Place a funnel in the oil fill hole in the valve cover.

Pour a quart of oil into the funnel and let all of it drain and collect in the oil drain pan.

Since very little of this oil will remain in your engine, you may want to use the least expensive oil you can find for this.