The title is a bit misleading, but whatever. I wanted to delete the credentials in Windows Credential Manager on a remote machine. I didn’t want to delete any particular credential – what I suggest below won’t work for that – but simply all the credentials stored for a particular user.
What you need to do is go to the C: drive of that remote machine and then
C:\Users\<the user>\AppData\Roaming\Microsoft\Credentials. You may not see anything here as they are System files and hence hidden. But once you do the needful to see them, delete all the files present here and the credentials are removed.