[Yaaarc] Repairing LEGO motors 71427

[Jim Ronald]

I was hoping to assemble a quick and dirty LEGO Sumo for the upcoming Sumo Contest.  As luck would have it one of my Lego motors (old gray 71427) is seized up.  I'm pretty sure that the motor worked fine when I put it away 5 years ago.  It was easily able to remove the back cover but I can't seem to disassemble the motor any further.  I googled and could fine no active disassembly instructions.  I did fine one reference that said the permanent magnets are made of sintered magnetic power which seems to turn to dust in about 1/3 of the motors.  If anyone knows otherwise please let me know.   

Thanks
Jim Ronald