For many years I have owned a bosh pf 50 router but never used it. When I attempted to there was no rotation. I manualy rotated it. It freed it a bit. but it was not rotating freely. I have tryed to dismantle it to free up any parts that need to be. I have taken the top half off but don't know how to take the lower caseing off. any help would be appriciated. Ta Peter