I'm looking for a little help here. I would like to replace the tires on my 36" Gravely Belt Drive WB. However, I'm having trouble removing the wheels from the unit. On the left hand side, there is a large nut that I've tried to remove, but it just turns and turns and I can't get it off. On the other side, there was a snap ring and a washer which I also removed but neighter wheel will come off. I'm sure there is something basic that I'm overlooking here. Any help would be appreciated. I thought this little project will be simple, but I guess I was wrong. Thanks Again.