Documents Folder Location Manually Set to Server That is Being Retired How to Move to New File Server?

Question

Currently on each machine in our domain, during system setup we have right-clicked on the documents folder, clicked on the locations tab and manually set the documents folder to \fileserver\users\marvin_mathieu. This file server is currently being retired and I would like to figure out a way to make it so that the documents folder is redirected to a share on the new file server without doing this manually on every PC. I've seen guides online but I haven't seen any that touch on making this work when the old folder network location is set manually outside of group policy.

How can this be done? Help is much appreciated.