The hash will start from the 7-11 near the bottom end of Sukhumvit Soi 22. It's situated on an angled crossroad opposite the Tonkoon restaurant. 

Either Asok BTS or Phrom Phong BTS is convenient for Soi 22 which has a Holiday Inn on the junction with Sukhumvit. 

Walk down Soi 22 on the right hand side, past the 7-11 opposite the Imperial Hotel, past the 7-11 after the Green Parrot, past the 7-11 near Honey House 2

You'll pass a Fire Station on the right and the 7-11 you need is shortly after that. 

Allow at least 15 mins to walk from either BTS or get a motorbike taxi, there are plenty about. 

As an alternative take the MRT to Queen Sirikit Centre leave by Exit 1 and follow the arrow/markings. Only Exit 1 will have markings.

Best to bring a torch as it's dark and uneven ground where we will go.