Why, exactly, would the Cavs have to be willing to do that?
If Sexton just wants to play elsewhere, the Cavs can pull the Q.O., release the cap hold, and let him sign for as much money as he can get.
They don't have to take back bad money and shouldn't.
Cavs would have to be willing means they would have to want to make the trade. Not that they would have to make the trade. The key word was willing. Sextons agency can try to get offers from other teams then see if the Cavaliers can work out a sign and trade with any of those teams. But the Cavs would have to be willing to do something like that.