Retrofit and TUTD with LSA, 6L90E and E67 controller

Doing a new project, a LSA with 6L90E from a Camaro Zl1 2013, E67 is going into to Impala 1959 Coupe.
I am new to the E67 and the new generation of transmissions...and CAN so I got some problems here :)
Going thru the stock harness making a retrofit of it I learn alot!

I am at the point where I want to use the stock steering column shifter but when going into M (manual) mode I want to be able to tap shift.
Have been doing some research and its seems on the Camaro the buttons communicate with the BCM that sends a CAN message to the TCM.


Looking in the tune I can change D9603 to Wired switch.
Whats the pinout and what ohms should the up and down shift be?


If this is not the way to go then I got some options I guess.

- Wire in the BCM (I got the cars BCM) and connect the buttons like stock
Would be nice to wire in the BCM but I guess its hard to do and needs BCM programming?
- Wire in an external CAN interface but then I need the CAN adress right?

Anyone got any information about this?
Have been reading about the E67 controller but all I see is "change to E38", is it so hard to get into?