There isn't an MRT to gets to Dempsey Hill but there are some shuttle buses listed on their website (http://www.dempseyhill.com/location.htm) There are also quite a few public buses that pass by. Most of them can be boarded from Orchard Road. And then it is a short ride and walk to Dempsey.
Please see the map on their website for the location of Block 9 (http://www.dempseyhill.com/location.htm)
If you are really lost, you may call Andrew at 91070735. But only if you are really lost. If you are late, no worries, just look for sketchers scattered around the area and approach any of them. I don't think you can miss us.
See you there! Remember the new timing. 9AM-12PM. Merry Christmas!
There's a giveaway contest also, sponsored by ParkaBlogs.
Participate at goo.gl/sO1i7w
These are the prizes.