(a) The City may lease, sell or dispose of real property not restricted from lease or sale which the City Council has determined is not required for a public purpose by any lawful method or mode of conveyance or grant. Any instrument requiring execution by the City shall be signed by the City Manager and attested by the City Clerk. The form of any instrument shall be approved by the City Attorney. Lands leased, sold or disposed of must be of appropriate size for the intended development or use to meet the intent of this chapter. Council may require a subdivision prior to lease, sale or disposal of lands.