507.186.  Substitution of conservator for next friend or guardian ad litem — effect of contracts. — 1.  At any time during the preparation or prosecution of such action or claim, before or after judgment or appeal, the minor's duly appointed conservator may be substituted for the next friend or guardian ad litem.  The substitution may be made by the court or the clerk thereof upon an ex parte showing of the appointment and qualification of the conservator.  In the event of such substitution, the court shall, upon payment or transfer of all of the minor's money or property in his hands to the conservator and filing a receipt for the same with a certified copy of the conservator's letters attached to it, and acceptance of the receipt by the court or clerk thereof as authentic, discharge the next friend or guardian ad litem from all of his obligations and duties as such.

  2.  In the event the minor's conservator has been substituted for the next friend or guardian ad litem and the attorney fees and expenses have not, at the time of the substitution, been paid, the conservator shall be bound by the attorney fee contract and shall be obligated to pay the attorney fees and expenses to the same extent as the next friend or guardian ad litem would have been obligated to pay them had he not been discharged, provided the attorney fees and expenses are approved by the court.