Government Code § 50022.7
ARTICLE 2. Powers and Duties of Legislative Bodies
If at any time any code which any local agency has previously adopted by reference, shall be amended by the agency which originally promulgated or adopted it, then the legislative body may adopt such amendment or amended code by reference through the same procedure as required for the adoption of the original code; or an ordinance may be enacted in regular manner, setting forth the entire text of such amendment.