Presidential pardons apply only to federal crimes, and he does not have the power to deschedule anything. He has the power to ask the dea to request the scheduling be reconsidered.
Lincoln didn't have a chance to end slavery either but found a way to get it done... even without immunity to do virtually anything, as an official act of the President, to compel cooperation.
Lincoln kind of ended slavery, but only in a territory he was at war with. He never actually did anything through standard political means. In fact he wasn't even opposed to slavery, he just used abolition to help preserve the union. The true end of slavery in america occurred with a constitutional amendment.