try lots of penetrating fluid. If you can borrow or rent a 3/4" impact (and appropriate socket), that is best.
A small story: about 20 years back, we'd bought a used car and I dragged my 18 year old son out to help break the wheel nuts loose (over his 'why' objections) . I had an el cheapo 1/2" drive impact that got most of them off, plus borrowed a 1/2" Ingersoll Rand impact; etc. etc. etc. The final wheel nut did not want to come loose. Dan (my son) was over 200 pounds at the time, and we put him on the end of my unbreakable Craftsman socket and unbreakable Craftsman breaker bar and a five foot snipe (i.e. we're at least 1000 foot pounds of torque here) and he climbed on the end of the snipe and bounced and... the socket broke. Replaced the unbreakable socket with an impact socket, and we got it off - he figured the old man wasn't as crazy as he appeared.
Try heat; try penetrating fluids of your preference; order a new main seal as you'll need it anyway. And whenever you get work done that means the wheels come off - or buy a used car - take off the wheel nuts and torque them properly, as even road side assistance couldn't have gotten that last #$%^&* wheel nut off. Doug