Changing a wheel cheaply - big breaker bar vs cordless impact wrench?

I need to switch a drive wheel from my parts truck to my road truck (one tire is going bad prematurely). I'm not ready to invest in air tools right now. What are my options for getting the lug nuts loose?

I was considering getting an impact wrench for my 18 volt Ryobi collection, but the strongest one they have is 300 lb/ft torque and I was told the nuts are sitting at 475 lb/ft. Has anybody had any luck with using something similar?

Another option is to just get a great big breaker bar. Would that work?

Not too worried about correct torquing, I have a TA 10 miles away that I will go to for proper torquing with their ridiculous $1000 torque wrench.

 

Wow, I didn't even know about these things. This definitely has the potential to be dangerous.

 

That's a bit steep, for that price I can get a cheapo compressor and air impact from Harbor Freight...

Also, I kind of want to stick to the same tool family and I'm already deep into a Ryobi collection. I wish they had a strong impact drill like that.

 

Of course. I wasn't gonna use all that for getting the lug nuts off. I just wanted something that at least approximates the correct torque when I tighten them after switching the wheels.