The resignation really ought to be submitted to the secretary of the electing assembly in writing.
Unless something else is provided in the bylaws, the resignation must be accepted by the electing assembly. This is done by adopting the motion, Request to be Excused from a Duty, by majority vote. See RONR (12th ed.) §32.
The member may withdraw his resignation without the permission of the assembly until the chair has stated the question on the adoption of the motion to accept the resignation; thereafter, the assembly's permission is required.