If there is no 6-pin socket you will have to cut the track on the motor backplate to isolate the LH brush holder (as you look at the motor). Follow the below for connections ;
Red-pickup from track.
Black-chassis.
Orange-RH brush.
Grey-LH brush.
White-front lights.
Yellow-rear lights.
Although these motors are regarded by some as a little crude they will run very well with a decent decoder - it is very important that the locomotive runs well & free before conversion - if not a good service & a commutator clean will benefit.
Make sure that you use a decoder that will dim the lights, otherwise they will look like searchlights & possibly damage the body (an alternative is to use 24v bulbs or even modify to fit LED's).
Hope this helps.