Move tasks to another task type

{
  "dealTask": {
    "dealTasktype": "2"
  }
}

{
  "dealTasks": [
    {
      "automation": null,
      "cdate": "2017-06-01T15:08:55-05:00",
      "dealTasktype": "2",
      "doneAutomation": null,
      "donedate": null,
      "duedate": "2017-06-02T12:00:00-05:00",
      "duration": "0",
      "edate": "2017-06-02T12:15:00-05:00",
      "id": "1",
      "links": {
        "activities": "/api/3/dealTasks/1/activities",
        "automation": "/api/3/dealTasks/1/automation",
        "dealTasktype": "/api/3/dealTasks/1/dealTasktype",
        "doneAutomation": "/api/3/dealTasks/1/doneAutomation",
        "notes": "/api/3/dealTasks/1/notes",
        "owner": "/api/3/dealTasks/1/owner",
        "taskNotifications": "/api/3/dealTasks/1/taskNotifications",
        "user": "/api/3/dealTasks/1/user"
      },
      "note": "Call Steve",
      "owner": {
        "id": "1",
        "type": "deal"
      },
      "relid": "1",
      "reltype": "Deal",
      "status": "0",
      "title": "",
      "udate": "2017-06-01T15:08:55-05:00",
      "user": "1"
    }
  ],
  "deals": [
    {
      "activitycount": "2",
      "cdate": "2017-06-01T15:08:41-05:00",
      "contact": "1",
      "currency": "usd",
      "edate": "0000-00-00 00:00:00",
      "group": "1",
      "hash": "3abd127b",
      "id": "1",
      "links": {
        "activities": "/api/3/deals/1/activities",
        "contact": "/api/3/deals/1/contact",
        "contactDeals": "/api/3/deals/1/contactDeals",
        "group": "/api/3/deals/1/group",
        "nextTask": "/api/3/deals/1/nextTask",
        "notes": "/api/3/deals/1/notes",
        "organization": "/api/3/deals/1/organization",
        "owner": "/api/3/deals/1/owner",
        "scoreValues": "/api/3/deals/1/scoreValues",
        "stage": "/api/3/deals/1/stage",
        "tasks": "/api/3/deals/1/tasks"
      },
      "mdate": "2017-06-01T15:08:55-05:00",
      "nextTask": "1",
      "nextdate": "2017-06-02T12:00:00-05:00",
      "nextdealid": "1",
      "nexttaskid": "1",
      "organization": null,
      "owner": "1",
      "percent": "0",
      "stage": "1",
      "status": "0",
      "title": "New deal",
      "value": "10000"
    }
  ]
}