You have to do it at the bye week. You have to remember half these coaches are personal friends of Denny, the odds are pretty good if you just fire Denny, that Solomon, Hargraves and maybe some others are either going to quit or mail in the rest of the season. You have to go into the bye week, fire him after the Packer game and spend the rest of the bye week with the new staff.
You spend this week quietly seeing if you can line up people that are willing to take the jobs, and then you fire Green.
It's not going to pretty interim never is, but Green is probably going to exit in a very ugly fashion anyways so you might as well give yourself an extra week to get over it.