If a sign not legally in existence at the time this chapter is adopted does not conform with the requirements of this chapter, or if the construction, design, manner or use, or method of anchoring or supporting any sign makes such sign unsafe, the City Building Official shall proceed in any manner he deems necessary to cause the removal of the sign or the rebuilding of the sign to conform with the requirements of this chapter, the Uniform Building Code and any other applicable laws. (PZSC § 03-13-009)