The first bus to Tsuen Wan Railway Station Bus Terminus will be leave at 05:30 a.m at Yuen Long(West) Bus Terminus
Times:35 mins(not included the waiting times and walking times)
KMBbus No.68M information:http://www.kmb.hk/chinese.php?page=search&prog=route_no.php&route_no=68m
Hope above information can help you!