"Take East Rail to Tai Po Market Station, exit via Exit B, turn left, follow trail to Kwong Wai House, Kwong Fuk Estate. It takes about 10 minutes."
see map below...
If you are interested in coming along for a run feel free to turn up as a visitor. You'll be charged HK$60 for a good run and as much beer as you can drink. The instructions above should lead you to the starting point of the run point "A".