You could sign-and-trade one of Kyrie or Kevin Love to OKC, or do a 3-team deal. We'd be under a hard-cap for the year, but, you could do it.
The problem with such a scenario is that you've somehow got to convince Durant that Cleveland is a better option than Golden State and/or Washington and/or Los Angeles (or wherever). And I just don't see a compelling argument that can be made there. If he doesn't want to play in Steph's shadow, why would he play in LeBron's? And if he wants to build his own team, why go to either GSW or CLE?
It's not that we don't have the assets, I think we do, it's that he just wouldn't come to Cleveland over the alternatives.