Not just Early Adopters, but a blend of all types of teachers. This helps other teachers that aren't so sure about "another new program" see that this is a method and practice that will helps students learn more effectively, and isn't just another top-down initiative that has to be strapped onto an already heavy teaching load.
Students can be the change-agents that you've been looking for. Create a structure that allows for capstones, projects at the end of units, a maker faire, or use clubs to start to showcase (To teachers and other students) what can be learned through rich hands-on innovation, design and making.
Use the d.school design thinking cycle to empathize, define, and test solutions to these problems. This also helps the teachers become comfortable with the process that we will ask students to also be owning.