I can get everybody there together, working on the same plan (though my only idea so far is nowhere near as good as I think we could get)...but the droids is where I get hung up as well. The footage we have to work with is extremely limited if we're hoping to change everyone's purpose. One would almost need costumes and droids to reshoot some basic material just to make it seem like everyone is in on the same scheme....

ex: Lando being in a head to toe costume makes it easy to fake new footage and have it fit seamlessly with whats already there. You could build a miniature hallway set, and film a double on greenscreen, from behind, walking away from the camera, down the hallway.......couple that with some of his trademarked suspicious glances and some new shots of hands doing "something"....maybe he's sending a signal to Luke, maybe he's rigging something specific for the escape attempt....hell, if you cobble together some dialogue from ESB you could maybe even have him passing by Han's cell and mumbling an encouraging message to him that Luke is coming soon to rescue them all.

If you wanted to fake something with the droids that would be even easier...or Leia in her bounty hunter costume......all of it is primed for shooting new material as they're almost ALL unrecognizable...only Lando has a bit of a facial restriction for what one could possibly shoot....but even that is minimal.