The charter of any municipality adopted under the provisions of Article 10, § 6 of the constitution of New Mexico, by law of the territorial legislature of New Mexico or under the provisions of the Municipal Charter Act may be amended or repealed either by a proposal submitted by the governing body of the municipality to the qualified electors or by petition as provided for in Section 3-15-4 N.M. Stat. Ann. for the adoption of an original charter at a general or special election and ratified by a majority of the qualified electors voting on the amendment or repeal.