I've had ours off a couple times. Each time all I did was slap the wheel on the back (toward the driver) side with both open palms. In your csae it sounds like someone has tightened the nut on the shaft (I'm assuming you removed the nut) way too tight.
You might need a steering wheel puller. It's similar to a 2 jaw puller but rather than grabbing the wheel with the jaws it uses 2 bolts in the holes to anchor the plate to the wheel. Then the shaft of the puller presses against the steering wheel shaft.
Here's a link to a steering wheel puller:
Steering Wheel Puller | AutoZone.com
You might be able to just get a couple proper size bolts and use your existing puller. Once you get some compression against the steering shaft hit the back of the wheel towards you with an open palm. It should pop off without too much effort. I would leave the nut loose on the shaft so when the wheel does come off it doesn't go flying and hit you in the face.
On Edit: I guess I was a little late with my response. Glad everything worked out.