To go to Grandpa Cedar, get on the bus bound for Haguro-Gassan (bus timetable) and get off at Haguro Zuishinmon mae 羽黒随神門前.
You will need to go down Mt. Haguro's stairway to see Grandpa Cedar. The stone steps can be very slippery after the rain, so please watch your steps. Bring rainwear in case of bad weather, and water supply during summer to prevent dehydration.