In a perfect case scenario we pay nothing and he's free to walk away. In reality I know that he won't leave without some cash, so I just hope they pay as little as possible.
As things stand, he's contributing ZERO to this club. You can offload him and finish the season as we are. At least the club saves up some money that way.
If we insert Rovella between January and June in Ramsey's place, we even have an instant upgrade. On much cheaper wages, younger and a much better fit for Allegri's game.
The whole situation is a win-win, as long as we don't pay too much of "severance" pay.