Section 4. The expense of abatement and removal shall be collected by the officer as damages and costs are collected upon execution, except that the materials of buildings, fences or other things so removed may be sold by the officer as goods are sold on execution for the payment of debts. The officer shall apply the proceeds to the expense of the removal and shall upon demand pay over the remainder to the defendant. If the proceeds are insufficient to defray the expenses, the officer shall collect the deficit from the defendant.