If the decision is in favor of the plaintiffs, said commissioners shall direct the town, in writing, to make the alterations prescribed and fix the time within which the same shall be done, and if not done within the time fixed, the same may be done by the plaintiffs. Whether by the town or by the plaintiffs, it shall be done in a faithful manner and to the acceptance of the commissioners. Whichever party makes said alterations has a claim upon the other for the proportion fixed by the commissioners for said other party to pay, and if it is not paid within 30 days after its approval by said commissioners and a demand therefor, it may be recovered in a civil action.
38 M.R.S. § 774