I had the same problem with my Dodge dually, went to replace the tires and the store I went to couldn't get the rims off. They told me I'd have to take it some place else, I was shocked, I had NEVER heard of such a thing.
Come to find out it was more of a liability issue than anything else as they didn't want to be responsible for "damaging my rims".
Brought the truck back home, watched the videos, did the figure eight thing to no avail. Then talked to a tire installer at my local Good Year Truck tire dealer, he told me to just work on them with a large hammer, that's what they do. (go figure)
Finally took a huge breaker bar to them and low and behold I popped them off! Took me a couple hours but I got it. Cleaned the center holes and greased them up now NO MORE troubles! :)
Dan