Updating Stocking Type in Mass - JDE 9.1

We are going through a huge amount of cleanup in our system and wanted to see if there was a simple way to change the stocking type in mass. I tried using the R4101Z1 process, but got an "Item Location Not Found" error. I know it's dangerous to make that kind of change in mass, but it beats spending hours going screen by screen. Any help will be appreciated. Thank you!