Add-Type –Path "C:Program FilesCommon Filesmicrosoft sharedWeb Server Extensions16ISAPIMicrosoft.SharePoint.Client.dll"
Add-Type –Path "C:Program FilesCommon Filesmicrosoft sharedWeb Server Extensions16ISAPIMicrosoft.SharePoint.Client.Runtime.dll"


Function Get-Context([string]$Url,[string]$Username,[string]$Password){
   $SecurePassword = $Password | ConvertTo-SecureString -AsPlainText -Force
   $credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($UserName, $SecurePassword)
   $ctx = New-Object Microsoft.SharePoint.Client.ClientContext($url)
   $ctx.Credentials = $credentials
   return $ctx
}


Function Delete-NavigationNode([Microsoft.SharePoint.Client.Web]$Web,[string]$NodeTitle){
   $ctx = $Web.Context
   $nodes = $Web.Navigation.QuickLaunch
   $ctx.Load($nodes)
   $ctx.ExecuteQuery()

   $node = $nodes.GetEnumerator() | where { $_.Title -eq $NodeTitle } | Select -First 1
   $node.DeleteObject()
   $ctx.ExecuteQuery()
}



$Url = "https://contoso.sharepoint.com/"
$Username = "jdoe@contoso.onmicrosoft.com"
$Password = ""


$ctx = Get-Context -Url $Url -Username $Username -Password $Password
Delete-NavigationNode -Web $ctx.Web -NodeTitle "Recent"