With JDM opting in, the Sox need to decide how much they believe in Sale. If they just want to clear him off the books, they should be looking for a repeat of the Punto and Beckett deals -- for example, they could package JD, Sale, JBJ and a low-level pitching prospect for a top prospect, a short, bad contract, a bullpen arm and a couple of lottery tickets.
Unfortunately, I don't think JDM is playable in the field, so the teams willing to pay top dollar for him are limited.
That said, if the Sox were willing to take on Choo for a year (he's a FA after this year), the Rangers might be open to that kind of deal.
Mookie could also be part of such a deal, but I hope they would move Sale and JDM in order to find a way to keep Mookie.