Before any payment is made under this subtitle, the claimant: shall execute and deliver to the City an instrument, in such form as may be approved by the City Solicitor, assigning to the City all rights and claims which he may have against third persons as a result of the occurrence for which the claim is being made, up to the amount of the City’s award to such claimant; and shall fully release the City from all claims and liabilities of any kind whatsoever arising out of such occurrence, on a form approved by the City Solicitor. City Code, 1976/83, art. 1, §140(f) Ord. 67-1126