I am not finished with my vac, and the local water company has a swarm at home in one of their concrete meter boxes. Of course, they want my tail in there. This is a new one for me.....Any tips would help a lot.
As Hobie says, they could be unfriendly. Dress well, and carry a few cans of raid, just in case. If they are friendly, cut comb and brush bees off, one comb at a time. Move slowly and it will all come together. Each removal is different, so you just have to play it by ear.