This nut is the regular "righty-tightey, lefty-loosey" however, they are really torqued on there. You may need to use an impact gun to remove it. You can even use a little propane torch and heat the nut up as well, to assist in its removal.
Can I heat it up and then use a 17 inch breaker bar with a 10 foot plastic conduit pipe on it? I've tried it and it didn't work.
Absolutely. Heat the nut up and use what you gotta use for leverage. Worst comes to worst, go to a local, close garage and have them break it with an impact gun. Sock it down by hand, and you should be ok for a short drive back to where you are working on it.