The county clerk shall issue a warrant directed to the viewers appointed, setting forth their appointment, and requiring them to meet at the time and place named by the board of county commissioners, and to proceed to view and mark out such road and to assess the damages and benefits accruing to the owner or owners of any of the lands over which the same may pass, by reason of the alteration, changing, widening or location thereof, and the proper cost of opening such road for travel.