Making a new file server is great, everyone loves a brand new server with all the old cat videos Karen has pasted randomly throughout it(maybe enable data dedupe to save some space). This use case is for when you have an old file server that has been migrated to a new file server and you want the \\newservername\share to work but also want \\oldservername\share to work but it won’t unless there’s a server name alias.
Now the right way is to do something with group policy and update their mapped drives to your new server but there’s all that “I know more than IT does” and “I do what I want..WHY DOES IT BREAK EVERYTHING?” users so….
Verify the machine account no longer exists in AD, delete if you must as long as that system is no longer active. If it is then you’re just boned, this will not work.
From Admin CMD(ideally from that server):
NETDOM COMPUTERNAME [yournewserver] /add:[oldserver.windrammer.net]
Actually type COMPUTERNAME then the new server name.