A couple of similar trades for Nash and Zuccarello(one gets another forward, one gets another defenseman) and the rebuild is pretty much done.
Stepan, Zibaned, Kreider, Miller can play in the top-6 now. That's 4. Buchnevich probably will sooner or later. That's 5. Plus the Rangers get someone for Nash or Zuccarello. That's 6. Hayes had a sophomore slump, but there's a good chance he gets there, still let's leave him for the bottom 6: Hayes (36 points), Fast (30 points), Lindberg (28 in 68 games) can all be third liners immediately, and are young enough that they are improving. Jooris, Hrivik, the the usual couple of annual UFA signings (Grabner and Gerbe this year) fills out the bottom 6.
On Left Defense, McDonagh is on the first pair, Skjei should be at least a second pair and Graves (AHL All Star as a 20 year old rookie) at least a third pair with both having greater potential than that. On the right side, McIlrath is a quality top-6 RD already, acquire one more RD for Nash/Zuccarello and there's just one hole left, which can always be filled through free agency, especially on a team as young as this which would be well-below the cap limit.