Hi Jaco,
From Heidelberg on the R549 you will get to the crossing where you can turn left to Villiers or right to Vereeniging. You turn left to wards Villiers on the R54, and after about 15km you will see a board on your right hand side saying Boschkop. Turn right and stay on the dirt road.
Hope you enjoy. Please reply when you came back to say how it was.
Gert