(a) If the estimate of cost of making and completing the improvements according to the changed plans does not exceed the limit of cost to be borne by the landowners in the improvement district as limited by the statute in force at the time the second or majority petition is filed, or by a majority petition, the assessors shall immediately proceed to make a reassessment of benefits to be derived from the making of the improvements according to the changed plans.
(b) The reassessment shall be filed, advertised, and heard, and the time for any complaints against it shall be limited, as is provided for on the original assessment in the district.