I'm in the same boat with BHN. The BHN form says there is no way to get the user name and password . . . but sometimes the local BHN tech support will give it to you, I think you will have to tell them you want to open up some ports, don't say you want to change the SSID or passwords. Some how BHN gets the modem and flashes the modem with their settings and the default user name and password don't work. If you find out let me know. Almost everyone says we should tell them to put it in bridge mode and I guess they will do that but then you will have to buy a 3rd party router.
I'm not sure exactly but I think BHN came from TW. I know we used to have TW and one day it turned into BHN so maybe the local TW will help.