I am wanting to change the editor and author of a document in a document library in O365 using CSOM powershell. I have managed to change the dates like this :
$Upload = $List.RootFolder.Files.Add($FileCreationInfo)
$Context.Load($Upload)
$Context.ExecuteQuery()
$ListItem = $Upload.ListItemAllFields;
$Listitem["Modified"] = "2013-07-02T00:00:00"
$Listitem["Created"] = "2013-07-02T00:00:00"
$ListItem.Update()
$Context.Load($Upload)
$Context.ExecuteQuery()
but I am stuck with how to add people as $Listitem["Editor"] = "John Smith"
doesn't work