Should amendments to the agreement be necessary and if all parties are in agreement, an addendum to the agreement shall be negotiated subject to review by the city attorney for signature of the parties. Either party may propose amending the agreement by notifying other parties to the agreement in writing of the nature of the amendment and the reasons why the amendment is necessary. The party requesting the amendment shall be responsible for any costs associated with the preparation of the addendum to the development agreement, unless the parties agree to share the costs. Such cost sharing arrangement shall be determined and agreed to, by the parties, prior to negotiating the addendum to the agreement. Amendments must comply with the formalities of approval, including approval by the city council, which govern original development agreements. (2003 Code § 12-05-09)