From Badaling Great Wall to Changling, Dingling.

If I'm coming from Badaling Great Wall, I should take Bus 919 and get off at Ming Huang La Xiang Gong Station (The Ming Dynasty Wax Museum) and then transfer to Bus 314 and get off at Changling Station to get to the Sacred Way. My question is this: Is Changling Tomb walking distance (around 15-20mins) from the Sacred Way? Or should I take a short Bus Ride to get there? From Changling Tomb, how do I get to Dingling Tomb? Another short bus ride? What is your recommended itinerary if I'm coming from the Great Wall Badaling and I want to visit the Sacred Way, Changling Tomb and Dingling Tomb in a matter of 4 hours? Thanks.