Hire a president to oversee football operations. Maybe Derrick Brooks or Bruce Arians (retired from coaching but may take a role similar to Coughlin's in Jacksonville).
Replace Licht and his guys for someone who comes from a team that excels in player evaluation. I would see who is available in Kansas City, Minnesota or even San Diego.
Allow the GM to choose his own coaching staff. One example would be a combo of the Vikings director of player personnel (whoever that is) who brings in current Vikings OC Defillipo to act as HC.
Retain Jameis, but not necessarily to be the future QB. Jameis will have a clean slate with the new management but a very short leash. There will be a QB competition, likely coming from a 1st or 2nd round draft pick that the new scouting dept targets in the offseason. Jameis is essentially the 'veteran bridge' QB who either puts it all together and reclaims his role as future of the franchise, or the young guy replaces him.
I would keep the following players:
Chris Godwin
Mike Evans (would consider an early 1st round pick for him tbh)
OJ Howard
Ali Marpet
JPP
Justin Evans
Kwon Alexander
Adam Humphries
Vita Vea
Carl Nassib
(The rest are up in the air: yes that includes Lavonte, Desean, Brate, etc.)
Keep the above players, and other than that, blow the roster up. Look for veteran leaders in free agency and acquire as many draft picks as possible by trading guys like McCoy and Lavonte.