Signatures to the petition may be withdrawn at any time before it has been acted upon by filing with the clerk of the board of supervisors a declaration signed by the petitioner that states that it is the intention of the petitioner to withdraw his or her signature from the petition.
Source:
Section 6047.66, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=FAC§ionNum=6047.66..