Surrender of service tax registration

Dear Experts

We want to surrender our Service Tax Registration as  there is no business. As there is no business we have not applied for migration to GST also. Last 2 years we have done nil return.

Now please advice me how to surrender our registration i.e. what is the process for that.

We want to close this  before 31st Mar,2018. So pls advice me on urgent basis.

Thanks & Regards

Gupta