Section 43GB of the Principal Act is amended by omitting subsection (2) and substituting the following subsection:(2) For the purposes of subsection (1) , a notice of demand is to be withdrawn (a) in the case of a notice of demand served on a registered operator by a police officer, by the service on that registered operator of a withdrawal notice in a form approved by the Commissioner of Police and signed by a police officer; and(b) in the case of a notice of demand served on a registered operator by an authorised officer, by the service on that registered operator of a withdrawal notice in a form approved by the Commissioner of Police and signed by an authorised officer.