Hi Rohan,
Logically no user should change the raw print itself but the data which you want to see. This means if Ship-to address is XYZ and you want to change it to ABC then change the source in sales order Iin this case overwrite the address for partner function). Automatically it will pick the same in the print depending upon routine.
On the other hand if you mean to change format or content of the print then you need to modify the same in processing routines assigned to BA00.
Regards
Rahul