I think the OP has enough to go on at this point. Why don't we let him put some sharp blades on, use one or more of the techniques mentioned here and report back to us on his progress?
If I understand the OPs orginal posts here correctly, he needed a mower for his own lawn too and decided to get a used commercial unit, which is what I've seen recommended here over and over to homeowners. It sounds like he decided to put it to use to try to make a few bucks with it as well. A lot of guys mow a few neighbor's lawns for extra money, and you don't need to have a MBA to do that.
P.S. - Yeah, I did get a little chuckle out of picturing him going around in circles at full speed with his mower choking on clippings, but he asked for help, not ridicule.