For next summer try to bring Ederson or Hjulmand. Sell Koop. Buy 2 good defenders and bring Kolo Muani home.
Sell get/ rid of
Vlahovic
Kostic
Gati
Rugani
I would also sell Locatelli for 40m but JJ fans will have a meltdown so...
He is a flop and we should accept that, same as you accept some girlfriend cheated on you and wants to leave you. Seems like the end of the world but surely you will feel better without her. Same should happen with Koopmeiners.
He's unredeemable