Look for some kind of pin or bolt, maybe on the inner end of the tines shaft, maybe obscured by caked on dirt, or rust. Might have a nut, cotter pin, bolt, or something. And if the tines are rusted on, a bath of PB Blaster for several days might loosen them. If all else fails, a careful application of heat from a welding torch might work, too. Since the seals are already shot, it can't hurt them. Maybe some carefully applied heat from a small tank propane torch might work, too. Just don't blow yer head off, by getting too close to the gasoline tank!

Does anyone know the part number for the belts of Western Auto wizard tiller and a diagram of how the belts go on?

Model number & serial number might be helpful.