To use a Relocation token, go to the city view and click on any empty house then click move in. If you've played other Strategy Builder games think of it Like an advanced teleport. You keep all your stuff and progress if you move to a different location on the map. Relocating helps you move closer to crew mates, enemies you wanna cause drama with which means less time your roomies have to travel across the city. This even allows you to move yourself into a higher level zones Such as an Area with Arcade 2 or Bookstore 2 as opposed to bookstore 1 and arcade 1
If you have roomies out (on a "March," but this just means outside of the home), then you will see this error and be unable to relocate.