Have you considered purchasing or renting a hub puller?
I would suggest doing that, and I would also reinstall the steering wheel onto the hub, leaving the nut a bit loose.
While incrementally tightening down the hub puller, switch back and forth between tapping the back of the steering wheel spokes with a heavy rubber mallet and rocking the steering wheel by hand. Tighten the hub puller a bit more and repeat the process. As the steering wheel begins to move off the spline, you might need to loosen the nut a turn or two before repeating the process.
When I use one of these, I employ the use of a short ratchet socket placed between the end of the puller shaft and the steering wheel nut in order to spread the load exerted by the puller shaft onto the full face of the nut.