It's about discontinuing our "need" for oil. It's something we need to do anyway, since oil is getting scarcer by the minute.
A small example: if you live within walking distance of work, you don't need gas to get to work. It's an arrangement that one individual has the power to make. Now multiply that by millions.
The shift to post-oil life will be a major one, no doubt about it -- at least as big as the shift from pre-oil life was, but probably quicker. It consists mostly of "
making other arrangements," as James Howard Kunstler describes it. Walkable neighborhoods, ubiquitous rail and public transport, local and urban farming, localized economies, reduced consumption; the list is long.
Some things will require public mobilization and political will. Others can be done on an individual level: move to where things are within walking/biking distance, get out of debt, insulate the house, collect rainwater, grow some veggies, join a
CSA, meet your neighbors, get involved with them... There's quite a bit more, of course.
Postcarbon.org is a good resource that I'd recommend highly.
A lot of these choices we can start making ourselves. Soon enough, they're going to start being made for us just by the circumstances, so it doesn't hurt to get a head start!