Whenever the council shall deem any special assessment invalid or defective for any reason whatever, or if any court of competent jurisdiction shall have adjudged such assessment to be illegal for any reason whatever, in whole or in part, the council shall have power to cause a new assessment to be made for the same purpose for which the former assessment was made, whether the improvement or any part thereof has been completed or not, and whether any part of the assessment has been collected or not. All proceedings on such reassessment and for the collection thereof shall be made in the same manner as provided for in an original assessment. If any portion of the original assessment shall have been collected and not refunded, it shall be applied upon the reassessment and the reassessment shall to that extent be deemed satisfied. If more than the amount reassessed shall have been collected, the balance shall be refunded to the persons making such payments.