Can someone explain to me like I am a 6 yr old how to loosen the drive belt enough to put the variable speed sheath back together. I've been told to pry open the jack shaft. But apparently I'm an idiot because I can't get it to move. Variable speed assembly broke and popped out of sheave. I ordered replacement part but I'm too stupid to loosen a belt to put it back together. Thanks in advance for your very simple instructions.