If the person or persons required to execute the work or to do the thing fail, within the time specified in any requisition as aforesaid, to begin to execute such work or to do such thing, and thereafter diligently to execute the same to the satisfaction of the municipality until it is completed, the municipality or any person authorised by it in that behalf, may, after giving forty-eight hours notice of its intention by a notification to be affixed or posted upon or near the spot, enter upon the land and perform all necessary acts for the execution of the work or doing of the thing required; and the expenses thereby incurred shall be paid by the owners or by the occupiers, if such requisition was addressed to the owners or to the occupiers, as the case may be, and by the owners and the occupiers, if such requisition was addressed to the owners and the occupiers.