Using an appropriately sized socket and socket wrench, remove the oil drain plug. (In a pinch, you can use an adjustable wrench.) Twist counter-clockwise to loosen it.

Let the oil completely drain from the car and into the drain pan.

Replace (reinsert) the plug by twisting it clockwise. Tighten it with the wrench following the same clockwise motion.

After the plug is replaced, wipe it down with a dirty rag to clean off any outside oil. This ensures that oil will not drip onto the ground.