As always, start with the willing.  Find people who already have an interest in agility, in change.  Help people who already ‘get it’ to make tiny increments of change.  Build your own dream team by adding value around the organization wherever you can – a minimally invasive, grassroots campaign.  Go do some agile ‘stuff’ wherever you stand; bottom up.  Create an inspirational culture – and be vigilant about keeping negativity out.