How do l make above loco that is dcc ready in to dcc using a dz125 decoder
Remove the jumper clips on the light board.
Use the wiring color code chart in the instructions for the loco to match NMRA color to the proper hole.
Solder up and go.
The Dash 8 has the same light board....
http://www.bachmanntrains.com/home-usa/dwg/dwgs/N850X-IS001_2.PDF
Wiring diagram is on the lower left of the instruction sheet.