Restrict the WIP Accounting Class to defaulted in the Create Work Order Page

In the create Work Order page(Enterprise Asset Management) there is a field called WIP Accounting Class, In this field WIP Accounting Class is Automatically defaulted based on the WIP Accounting Class provided in the Work Order Defaults under EAM Parameters Or the WIP Accounting Class assigned to the Asset number,but the client wants to select the WIP Accounting Class by searching if there more than one WIP Accounting Class based on the type of the Work Order(Breakdown or Preventive) in the create work order page, So we need to restrict the default value to be populated and make that field