Converting Athearn Blue box RDC in DCC

[Montrealrail1]

I want to Convert my Athearn Blue box RDC in DCC but I do not know how to deal with the frame,I know how to do it with a current locomotive,but Budd RDC do not hae insulated frame and I don't know how to wirering it to be able to run in DCC..
Do anybody know how to do it?,I know how to irering the motor,but I'm searching the way to wirering the bottom frame..

I'M expecting to do and attenpt to convert it,but test it before by installing a jumper,that will prevent to burn the decoder..
While doing it,I will filming it,in case of successely result,I will have it in video..

But if someone had did it,I will be agree to get tips for wirering the bottom frame

[Backshophoss]

This is the "rubber band" drive??, I have converted 2 to DCC.
It can be done,using the 9 wire Digitrax/JST plug harness,a bit of time,and drilling,tapping 1 hole in the frame.
The process is the same as converting a Blue Box Loco.
!st, Remove the body shell,put it in a safe place,take off the strap that brings power from the truck to the motor,then remove the motor
and the drive shafts,service motor as needed.
2nd, Clean,service the trucks and replace as needed the rubber bands used to power the wheels,it is a good time to polish where the trucks
swivel for smoother operation,do the same on the post where the shaft sits in.
Now is also a good time to clean up any kind of "casting rot"(powder) and/or flash from the frame.
3rd,Remove the "feelers" from the bottom strap of the motor,polish the strap near where the brush spring touches the strap,
solder the GREY wire to the strap,after that cools down,INSULATE with electrical tape.
4th, top strap of motor,polish strap near where the brush spring touches,solder the ORANGE wire to the strap.
5th, Drill and tap the frame near where the motor sits for a 2-56 screw 1/4 inch deep,this will be for the BLACK wire.
6th solder a washer(2-56) to a piece of wire,then attach the washer to the truck with 1 of the screws that hold the truck together,
do the same to the other truck,you might have to grind off a tiny part of the frame to clear the screw. use the same kind of wire thats
used on the harness,these wires then soldered to the RED wire.
7th,Plug in a Dummy plug into the harness and do a no load test,to check if the motor runs.
8th, Put the entire drive back together and test for movement,if it runs OK,or needs to be tweaked with.
IF everything is OK, install headlight bulbs(BLUE,WHITE[fwd h-light},YELLOW{rev h-light},
put the body shell back on and enjoy