I picked up a like-new Kubota w5021scc commercial push mower on craigslist. It includes a pristine bagger, and a plastic mulching chute. Only problem is, I can't figure out how to adjust the handle to a lower position. Is there anyone out there who can give me directions, or who has an old shop manual for this model? Or is it possible that the handle was designed to be fixed rather than adjustable? Thanks in advance for your help.