Some of the best advice I ever read was on a post somewhere on BYC I think that said, "make pets of your hens but leave the roosters alone. They are not pets". I've adhered to that advice and have 4 roosters in our flock that are for the most part excellent birds. I culled two for aggressive behavior towards humans and other roosters. Don't get me wrong, there is normal aggression between roosters, chasing roosters of lesser social standing to the the parameter of the flock and away from the hens, then there is abnormal aggression between roosters where two roosters get a higher ranking roo cornered and try to kill him. We wound up with an Welsummer roo with a permanently damaged hock that will probably be his end some day thanks to the latter.
I would say that if you haven't started conditioning a young cockerel from the moment they sprout feathers, you will have a harder time doing it now that he is an adult bird. The cast has been set as the old saying goes. Personally even if this bird did respond to conditioning, I would be scared to death to turn my back on him. Your wife, first and foremost, is being terrorized by this bird. I know for a fact that my husband would be loading up his .22 and I would be sharpening up the ax if one of our roosters seriously attacked me. Trust me, she along with your hens will be thrilled that the little tyrant is in the stew pot.
There are a lot of really nice roosters in this world to put up with a stinker. Even with a nice rooster you may occasionally have to adjust his attitude. There are many good articles on BYC teaching you how to do that. I prefer the 'walk of shame' approach where you walk purposefully towards your rooster as if you are going to run him over and make him get out of your way followed by catching him and carrying him around with you for 10 minutes in full view of the other roosters. Really makes them pause and watch. Roosters hate being carried around.
If your hens are free ranging, I would keep a roo with them. Our boys keep a close watch out for predators and even scream out alerts if wild turkeys come too close to the run.
Good luck, I know from experience that this is a hard decision to make. One way or another do what is best for you, your family and your flock.