According to Osho, sleep will come naturally—indeed, more skillfully than usual—and however it arrives, it is sufficient and no obstacle. The real work is nonattachment: discovering an inner point that remains outside all involvement. Then, even amid crowds, work, or eating, you stay a witness—present yet unattached, acting yet inwardly free.
Don't worry about sleep; it will come by itself—just keep a little space inside that watches everything without sticking to anything.