I don't get the replacing Barza bit? He hasn't played yet this year, and we still have by far the best defense in the league. I doubt we're thinking we really need to replace him with a starter, more so a younger prospect with good potential. We'll likely have Bonucci, Ogbonna, Chiellini, Rugani. That's by far the best set of CBs in Serie A, and probably top 10 in Europe. Add in Cacares who can also play CB if needed.
Why do we need to replace Licht? He won't be that old. 31 if I recall properly...
Pirlo. Well, he's more so holding us back at this point. Marchisio is better in that position now anyways, assuming we shift to a 4-3-1-2 or eventually a 4-3-3, replacing Pirlo isn't necessary at all, it's more about getting a decent AM, or some wingers. We'll have Vidal, Marchisio, Pereyra, Sturaro in mid, and a 5th perhaps bought with some of the Pogba funds.
Some of the Pogba funds will need to go towards buying a replacement for Tevez, assuming we don't have two future stars in Morata and Zaza (unlikely).
Really, all I see for that summer, is replacing Gigi, Pogba, and Tevez. Pirlo and Barza already have basically been replaced in the club. Still no easy task, but we have this coming summer, and the next one to deal with it, and assuming we sell Pogba, we'll have a massive war chest one of those summers.