If I were you, I'd call my local extension office to see if there is a local bee keeper's association. They would be able to advise you and perhaps even come out to hive the bees. I've seen that done a couple of times; it's an interesting process.

Generally speaking, swarming bees will move on to a truly suitable location in a couple of days. They typically pose no threat during this time, since they aren't defending anything, but it can surely be disconcerting having a swarm of bees next to your walkway!