Dave, I would have thought that some members with 782 knowledge would have replied by now. But here it is, a day later and ....nothing.
So... in spite of the fact that I know nothing about a 782, I will try to help you. I am going to assume that your steering wheel is held down by a nut threaded onto the top of the steering shaft and that the wheel is "keyed" to that shaft. The best penetrating oil is one you can make yourself. Buy a pint of the red ATF fluid (automatic transmission fluid) and then buy some Acetone which is also known as nail polish remover at the local drug store.
Mix a small quantity 50/50 and drown the area where the wheel and shaft are repeatedly for a few days. Check the underside of your steering wheel to see how it is constructed. Many wheels have a metal hub set into the plastic wheel. However, the outer edge of the plastic often hangs lower than the hub.
If you have the space to get a tool called a "bearing splitter" installed below the steering wheel, then you need to fabricate some steel spacer/s to prevent the bearing splitter from contacting any part of the plastic on the wheel. You want the splitter to apply its force directly against the metal hub. The splitter should not be tightened against the steering shaft. It just needs to be close to it.
Use a sharp punch to mark the center of the steering shaft and then use a 1/4 " drill bit to create a shallow crater there. Back the nut on the steering shaft off until it is flush with the top of the shaft and leave it. You are now ready to install an appropriate puller onto the bearing splitter and the top of the steering shaft. Depending on your steering wheel, that might be a two, three or four jaw puller.
With the puller snugged into place, use either a wrench or impact gun with a socket to apply pressure to the puller. If the wheel moves right away, then continue rotation until the wheel is off. If the wheel refuses to budge, then smack the top of the puller screw with a one to two pound hammer. Try tightening the puller screw again. If it does tighten, then that means the wheel moved.
Continue until the wheel hub contacts the steering shaft nut. Remove the jaw puller and inspect the top of the steering shaft for damage. If need be, tighten the nut one turn and clean up the damage with a Dremel tool When you are satisfied that the threads are OK, remove the nut from the shaft. Try pulling the wheel by hand using only medium pressure. If it refuses to move, then re-install the jaw puller and continue to extract the wheel. Keep adding penetrating mixture throughout this process.
Manual force on steering wheels can often cause the plastic to separate from the center hub, rendering the wheel useless. Patience and care will make the difference between success and failure. Good luck. Hope the above helps.