Simplest/best would be to simply ban the importation of oil in a single day, same as stopping smoking. That would mess us up about as badly as we were messed up in WW-II for about a year. You have to be smoking crack. That would 'mess us up' about as badly as if we had lost WWII. You rip even 10% off our oil supply and the economy goes into a tail spin. Take away 60%, and it totally collapses. It wouldn't be gas lines or fuel rationing -- it would quickly be bread lines.
The biggest and most immediate part of the trick would be to get rid of 60# of the commuting; that could be done very quickly, in a couple of months or so, with neighborhood work sites. In any given metro area there simply cannot be more than about 20% of the workforce which needs to be in a given place five days a week; everybody else could working four of those days from neighborhood sites which they walked to or drove half a mile to, and that would empty our highways.
In fact God could come down out of the sky right now and give us all the gasoline we'd need for the rest of our lives and it wouldn't solve the problem; you'd still have people spending three to five hours in traffic every day in metro areas getting to and from work. At some point the psychiatric bills are going to be more than any nation could afford.