Exporting the Part instance model

• I have a part instance file in abaqus profile prepared through hypermesh
• I will import that assembly and make necessary changes in the file
• I will export the file back, but whatever the changes made in the model is not updating 
• If i import it again after exporting, it will import the same old file (Basically .Inp files of parts is not Updating when i export it)

Please help me to get the answer How to export the Part instance model after importing into hypermesh