As an alternative method of apportioning the reassessments, the legislative body, if it determines that it appears that the assessments upon some of the lands to be reassessed seem excessive and not in proportion to benefits, may by resolution direct that the superintendent of streets spread the proposed reassessment upon the parcels of land to be reassessed in accordance with the benefits derived from the acquisition or improvement, or acquisition and improvement, to pay for which the outstanding bonds were issued. If the alternative method of apportioning is used the superintendent of streets shall estimate for each parcel to be reassessed the benefits derived from the acquisition or improvement, or acquisition and improvement, to pay for which the outstanding bonds were issued, and shall credit to each parcel all amounts paid upon the assessment (excluding penalties and interest), and the balance remaining after these amounts have been credited shall be the amount of the reassessment upon the parcel.