change output type medium for the printer from 1 to 6

Hello,

My query is new purchase order has been created with output type & medium as 1. And purchase order is saved in the system. But now user wants to  change the same from medium 1 to 6. Its showing output for partner already processed.  And message output is successfully processed in ME9F.  Is it possible to change the medium for purchase order which is processed?

If there is any report or user exit, enhancement to solve this issue?

Kindly suggest

Regards

Subbu.