I have done this..
You need a 'chunky' decoder. I have tended to use a Massoth XL, combined with a Phoenixsound card for the sound.
However, I would most likely use an ESU, or Zimo, combined unit these days.
If this is an Aristocraft model, be very aware that the motor and pickup wires may not match colours (for function/polarity) from both power-bogies.
These units are not particularly 'DCC friendly' and getting the lighting to work can be a challenge. - I cheated, and used a DPDT relay, to reverse polarity into the existing board, to give directional lighting.
You can still arrange to turn the lights off by DCC command, and have the manually switched option of day or night running.
PhilP.