You can change the user a couple of ways, the easiest would be if you have MPEX, VESOFT and using the ALTFILE command.
ALTFILE ZIPJ;CREATOR=MGR.ACCT1.
If you don't have MPEX, you can make a copy of the file, rename the existing file, the copy the file back to its original location. The user will now be how you are signed on.
Thx