I've got a Heljan Class 47, number D1100. It's not a good runner and at first glace the wheels look like they need good clean. However I am stumped as to how to get access to them - is there a way to get the plate off the bottom of the bogies, or is it a matter of rubbing each wheel as much as I can, then applying a little power to turn the wheels slightly? I'm hoping that I will not need to unplug all those electrical clips to the PCB (6), remember how they faced, and get in through the top.