The bonds may be sold, or exchanged at not less than par and accrued interest with the holders of the outstanding indebtedness in payment thereof. If sold, the funding or refunding bonds shall be sold in the same manner and under the same provisions as provided in R.S. 38:1653, and the proceeds thereof dedicated exclusively to the retirement of the existing indebtedness of the district or sub-district.
La. R.S. § 38:1672