Conflict resolution for drunken and violent patrons?!
Having done some bartending for about 8 years in Dallas TX, I have some insight. Being the bouncer, once you are involved and having been called to a situation, this patron is already agitated and probably ready to 'throw down.' There are no magic words you can say here, but you can diffuse the situation somewhat by your demeanor. Most people, when encountering someone drunk and being a nuisance, automatically think, "Oh, now i have to deal with this drunk." Change that. Never be demeaning or aggressive with your initial approach. In a mutual respectful way, tell them (calmly) it's time to talk man to man. "I'm treating you with respect, treat me with the same respect." "Now, let's step outside and talk about this." Now you have them out of the club. Any overt action here will only serve to escalate the situation.
Now, on the extreme end of this, the person is really intoxicated and (at this poiint) probably on more than just liquor and they just can't be reasoned with or handled other than being physically removed from the club. But be sure you have either Security or Local Police to document what happened to cover your a$$. But what you describe is the bouncer's burden. If everyone could handle their high, we wouldn't need bouncers.
"I am removing you from this private establishment. If you resist or make a move against me, i will call the authorities and you will be arrested"
that would get me moving more than a chance of getting knocked around
You can't reason with a drunken idiot. Either you need to look for a different job or you need to start enjoying beating up drunks.
Tell them that you don't want to see them get hurt and you are removing them for their own safety.