One of my hives became overly aggressive a couple of months ago, and I had to get them out of my yard in a hurry to protect the neighbors. Their problem was Chronic Bee Virus. Symptoms of the bees with the virus was no hair (sometimes called "greasy bees", and wings stuck out at right angles to the body. I had noticed earlier that there were strange looking, undersized bees in the hive. I realized later that they just look smaller without hair.
I moved all of my hives and requeened them with a hygenic queen (BeeWeaver). It took a good month for the bees to calm down. Every time we opened the box we got swarmed, and looking down into the box you could see the war between the bees going on. Healthy bees were trying to push out the sick bees, who didn't want to leave. Every time we went to our new apiary, we saw hundreds of dead bees on the ground. But the new queen did her job, and now the bees are calm and healthy looking.
I was reminded that there is no quick solution to aggressive bees, and that there is usually some kind of stressor in the hive that triggers the aggression (unless you have Africanized bees, which is not likely to be a problem for you).
Good luck figuring it out, and keep us posted.