src/IronMQ.php
public function replaceSubscribers($queue_name, $subscribers_hash)
    {
        $this->setJsonHeaders();
        $queue = rawurlencode($queue_name);
        $url = "projects/{$this->project_id}/queues/$queue/subscribers";
        $options = array(
            'subscribers' => $subscribers_hash,
        );
        return self::json_decode($this->apiCall(self::PUT, $url, $options));
    }
public function replaceSubscribers($queue_name, $subscribers_hash)
    {
        $this->setJsonHeaders();
        $queue = rawurlencode($queue_name);
        $url = "projects/{$this->project_id}/queues/$queue/subscribers";
        $options = array(
            'subscribers' => $subscribers_hash,
        );
        return self::json_decode($this->apiCall(self::PUT, $url, $options));
    }
Replace old Subscribers with new ones, Older subscribers will be removed.

@param $queue_name
@param $subscribers_hash - Array of subscribers. keys:
- "url" Subscriber url
- "name" Name of subscriber
@return mixed