Although this is not an official trail, the trail is quite well established and easy to follow. Where things get a little tricky, simply follow the rock cairns. Also, the final ascent up the pyramid itself is rocky and will involve some scrambling. Nothing too difficult, though. Finally, elevation gain is 4100ft, NOT the 1202ft shown here.
The main concern is finding the beginning, which is just on the side of the road. The trail starts shortly uphill from the electronic sign on Highway 50 between Strawberry and Twin Bridges. Looking uphill, there is a milepost on the right side of the road shortly uphill from the sign. And the trail begins just across the road to your left.