How do you change oil on a 4 stroke troy bilt weed eater?

To change the oil on a 4-stroke Troy-Bilt weed eater, first ensure the engine is cool and then place the unit on a flat surface. Remove the oil fill cap and drain the old oil by tipping the weed eater slightly to allow the oil to flow out into a suitable container. Once drained, refill with fresh oil through the oil fill opening, using the recommended oil type as specified in the owner's manual. Replace the oil cap securely, and check the oil level to ensure it is within the recommended range.