That looks a lot like my BEFCO tiller. I put new bearings in a couple of years back. If I can remember correctly
Remove chain tensioner- remove snap ring on top sprocket- now both sprockets and chain slide off as a unit. The lower shaft has a bearing held in by some bolts and retaining cups on both sides of the metal end plate. Remove the bolts holding the cup to the bearing. Pull cup then bearing from shaft. Now remove complete drive side of tiller. (The metal plate that encloses the drive side)
Now go to the other side of the shaft and the bearing will have the same retaining cups. remove the bolts and the shaft should come out with the bearing still on the shaft.
Hope you can understand my instructions.
Hope this helps.