/api/v2/projects/{id}/change_workflow

Switches the project to a different task workflow, migrating its tasks to the new workflow's statuses according to the map.

{
  "data": {
    "type": "projects",
    "attributes": {
      "workflow_id": 75,
      "map": { "101": 201, "102": 202 }
    }
  }
}