The movement has to start somewhere. Some communities will be more able to set up their local TDG than others. But as these early TDGs get established, other communities will become intersted.
To get started, I have listed three activities:
1) Let people in your social/internet circle know about the TDG.
2) Read the TDG books (all four are available for a free read from my website).
3) Talk to a few of your neighbors about setting up a TDG. If there is not much interest, approach them six months later.
The TDG is very much about neighbors getting to know one another a little better.
This Off-Medium link is my first TDG novel:
http://www.tiereddemocraticgovernance.org/dfp-chapter.php
Not exactly a great work of fiction, but it tells the story of USA's first TDG (fictionally speaking).
I used to belong to a political party in Canada. I was quite active in this party. Building a local TDG will be much less effort than my party work.