My suggested route for hiking Section 8 of MacLehose trail are as follows.
Take MTR to Tai Po Market (大埔墟) MTR station, then take a taxi to Yuen Tun Ha. If it is possible, you can also drive to Yuen Tun Ha directly.
Walk for about 1.5 miles along the Wilson Trail Section 7 to Lead Mine Pass.
Start Section 8 from the Lead Mine Pass.
Reach the end of Section 8. Take Bus 51 there to Tsuen Wan (荃灣) MTR station.
Some photos I took during hiking Section 8 of MacLehose trail are here.