OK, this is how I would do it - Remove that old one & check the spigot end size as I can't remember top of my head size of asbestos (make sure you get the same size).
Next check the depth back from inside to the stack, if you can get way with a fixed length 90deg connector then great if not then go with another extension & cut it to size then a bent 90 but it must have the socket to suit the old pans (No1) something like a MKB21 or 22 (page 70 in the below) but check cos I only had a very quick look.
You can now run the rest in 110 soil, couple of clips to stop it moving on all them flexible joints (solvent soil pipe please Jay we are pro's after all LOL) the soil will go into the Multikwik socket just put a good chamfer on the end, lub up both & make sure the Multikwik last fin you see is facing back down into the socket.
Don't need to tell you the rest.
Have fun.
http://www.multikwik.com/media/1047/e4649_ma_multikwik_tech-spec_book_finalpdf.pdf