Near the end of episode "Citizen Brown", after a cut scene where you talk doc into fixing the Delorean, Biff is unconscious on the floor and wakes up to attack you. The objective is to get Biff near the roulette table activated by the panic button. When Biff has you stuck behind the counter, you quickly need to select the records in the floor in front of you. Throwing the records at him will slow him down and allow you to highlight Einstien and give the order to attack. When Einstien attacks, it will drive Biff toward the roulette table. When Einey has Biff pinned against the table, select the panic button under the counter. It will activate the roulette table, unfolding it and knocking Biff unconscious.