connecting to a communal stack

[VirginPlumber]

hi,

im installing a saniflo into my apartment and need to drill into a communal cast iron soil stack. we have recieved permission to do this, but im just wondering if anyone can give me advice as to how I get between the stack and the wall to drill the hole without removing the soil stack? is it best to just go in the side and then use an elbow to connect it?

Its a daft question I know, with a very obvious solution I expect...!

cheers in advance

 

[seco services]

go from the side

 

[doitall]

And use an strapon boss for cast iron