I don't know about who goes first, but what matters most is how far on that list is the team itself. I'm worried that firing Adelman, trading Peja, etc. must be done carefully and precisely, or else the Maloofs risk alienating more fans.
While it may be best option for the franchise to stage a fire sale, go young and hope for the best 2-3 years from now, I worry that such a move would drive the remaining casual fans and corporate sponsors out, and the team will be gone before the hopes of contention return.
I think the plan was for a rebuilding on the fly to avoid this sort of catastrophe, but it may be inevitable nonetheless. No, I worry that nothing short of a miracle in the form of a Garnett trade may save this team, the franchise, and the city.