Requests to withdraw excess contributions shall be executed by members on forms prepared by the retirement system. Said forms shall inform members that the amount withdrawn may constitute income for tax purposes for the year in which paid, and that if so, the retirement system will report such amount to the Internal Revenue Service. The retirement system will pay the full amount of all excess contributions which are available to the member as provided in section 313.2 of this Part, unless the member elects to withdraw only a percentage thereof.