yes, there is a minibus (3.2$) from greenfield garden shopping mall to Tsing yi MTR , runs only in the morning between 8AM and 9AM. (not sure exact timing of last minibus). It is true that during summer very hot & humid and not fun walk. if you work in Tsim Sha Tsui area there are some special buses in the morning in front of green field garden. If you work central/sheung wan, wanchai , you can get Route No. 948 or 948x/p (30 minutes can reach sheung wan).