Haaland
or Sancho
or Grealish
in that order of preference. Can part-swap Martial if £80m doesn't cut it, although I'm not sure I'd spend more than £80m on Sancho currently.
Get Alaba in on a free, max 3-year contract, max wage same as Pogba (if he wants more than that, fair play to whoever coughs it up but he's not worth that to us). You get a top DM and a top CB all rolled into one, and I hear he's pretty handy at LB if we ever need more cover there. Only 28, too!
Keep Pogba. If he does leave, Grealish goes to the top of the list above, because Bruno must not be the only creative fulcrum in the squad.
Let De Gea go if a decent offer (50m+) comes in.
Continue to ship out other dead wood as and when it is sensible to do so. Dead wood does not yet include James or VDB, you maniacs. Mata can leave provided Diallo has shown he's not a total no-hoper by then.