Your Best Digs rated the Greenworks 22502 as the best electric lawn mower. The reviewer found this push mower easy to maneuver thanks to its lightweight design. He also liked that it was much quieter than the gas mowers he tested. However he noted that dumping the clipping was awkward since there was a crossbar in the way and he would have preferred it if the mower came with an extension cord. Greenworks offers the option of buying the mower with an extension cord for $30 extra.
Next you will change the oil. To lower oil viscosity and get it moving freely run the engine for a few minutes. Now shut the engine off and roll the mower onto a piece of cardboard or drop cloth. Close the fuel line (if your mower has one) and unhook the spark plug as before. Find the oil filler tube and remove its cap. Often the cap also functions as a dipstick.
Place a drip pan or other container on the side of the mower with the filler. Carefully tilt the mower so oil drains out and into the pan. Discard the spent oil into a proper disposal vessel. Now slowly pour fresh oil into the mower. For the specific type of oil you need check your instruction manual. Make sure to add only as much as your particular model requires. Remember to let the mower sit undisturbed for a few minutes so the oil settles properly inside the engine.