Fixing masport hoe diff ?

I have aquired a masport rotary hoe,briggs & straton motor,getting old.Goes ok but blades assembly needs sliding of axle shaft to get at dif as something amiss stopping blades turning when belt tightened.( turns with friction only).having removed the pins wont slide off axle as corroded to it....Any hints please other than penetrating oil and tapping to remove ? or dumping.