By Pete Eggink
In the picture above, one of Pete's SD-45's pulls a long coal train across a trestle on the Mason Dixon Modular Layout on 12/18/05.  This locomotive has only 3 motors instead of 4 but still has plenty of pulling power.  Why remove a motor from a perfectly good engine?  To conserve battery charge when running a battery-powered engine that already has plenty of power.  Current draw is reduced from 2.2 to 1.8 amps on level track.
Here are instructions on how to pull a motor, a process that takes about 45 minutes.
First remove the motor block from the locomotive using the outermost 4 screws between the wheels.  Then remove the cover using 8 screws, on the ends and between the motors.  The truck does not pivot at the center, so I recommend you pull the motor that is furthest from the pivot for better pulling power.
Now invert the block and pull up the motor lead clips.  Then flip the block over and remove the motor and outer wheelset.
Next the worm gear has to be removed so the axle will be free rolling.  Remove the axle screws and lockwashers.  Now place the assembly on a vise so that both sides of the wheel are supported but the gearbox is loose.  Place the tip of a needlenose plier on the center and give the pliers a tap to remove the wheel from the tapered axle.  Repeat for the other wheel.