The oil drains more easily when it has been warmed, but the generator needs to be turned off to change the oil. Run the generator for just a few minutes, then turn it off and allow it to cool before draining the oil.
Place the oil drain pan
Place an oil drain pan underneath the generator to catch the old oil as it drains.
Remove the dipstick
Unscrew and remove the dipstick.
Remove the drain plug
Use a socket wrench to remove the drain plug and let the oil drain out. Use the drain pan to collect the oil.
Reattach the drain plug
After all of the oil has drained out, reinstall the drain plug with a socket wrench.
Refill the oil
Refill with an oil recommended in the owner's manual and use a funnel to add in the new oil. Fill the oil until it reaches the bottom of the threads in the oil fill tube.