Here is the breakdown of the front coupler:
Simply solder your wire to the same rivet the coil is on the fiber board at the end of the coupler and coil assembly.
That wire then is routed to the rear truck and connected to the the pickup shoe solder lug.
Here you can see the breakdown of the rear tuck collection system, including the uncoupling shoe.
The entire set of service diagrams is kindly hosted by Olsen's: http://www.olsenstoy.com/2023.htm