A couple suggestions. Your practicality may vary:
- Win over one or two people: your boss, an intern, etc, over to your side first. Your first follower will make you a leader.
- Start pair programming or mentoring. Even if its just with an intern or two, working closely with someone can be a good way to influence their style. If you are willing, you could try becoming a manager.
- Give a technical presentation on the subject. Make the focus on the why and the problem you are solving, instead of TDD. You want people to buy into the problem rather than your specific solution. Include a couple other alternatives so it doesn't seem like you are just trying to push what works for you.
- Get some outside training from Object Mentor or the like. Works best if you can convince your boss and the team isn't a bunch of hardened soulless cynics.
