Support the wheel on some saw horses or similar with the box hanging down
heat the wheel and hit the axle with an air hammer
The 20,000 small blows a minute work a lot better than 1 big bang from a heavy hammer
Be careful not to flare the end of the axle
You can lay full body weight on the hammer before you pull the trigger.
I do them on mower with a pair of scissor jacks between the wheels & the body to put some weight on the axle and take the load off the internals .
Some have taken better than a day to shift.
They really rust on tight