How do you change oil in a Craftsman 6.0 Horse walk behind mower?

First, REMOVE SPARK PLUG WIRE FROM SPARK PLUG, as you will be working near mower blade.
Three inches from blade shaft, remove plastic bolt/plug with bare 3/8" drive ratchet extention, put in center of bolt, counter-clockwise of course. Wrench on outside of plastic bolt will work also.