PowerShell to remove item content type from a SharePoint list

Remove-ItemContentType.ps1

function Remove-ItemContentTypeFromAList(){
        #delete item content type from list
		Add-PSSnapin "Microsoft.SharePoint.PowerShell"
		$web = Get-SPWeb "http://YourSite.com"
		$list = $web.Lists["Your List Name"]
		$ctToRemove = $list.ContentTypes["Item"]
        if($ctToRemove)
        {
            Write-Host "Item Content Type Exist ready to delete"
            $list.ContentTypes.Delete($ctToRemove.Id)
		    $list.Update()
		    $Web.Dispose()
        }
        else
        {
            Write-Host "Item content type do not exists"
        }
}