I just went there to buy the magazine today... The place is as below.
I think walking in from the main Macpherson Road is the easiest. Bus stops along both direction of the main road is close by the Macpherson Lane that you walk in to reach the blk. Not far.
Assuming one is taking a bus there, outside this Macpherson road, there is bus no. 8, 62, 90, 151 only... earlier section of the Macpherson road that have Macpherson Centre, Siemens Building outside, Genting Lane, where it is before Winsor Hotel, there is also bus no. 61, 64, 65, 66 & 154. So if these are the buses you take from city to Macpherson road, you got to drop to change to 8, 90 or 151 at the same bus stop before they (61, 64, 65, 66, 154) turn away from Macpherson Rd to Circuit Rd.
Maybe many ppl won't know how to go to Macpherson Lane. I hope this helps.