export-webpart.ps1

function Export-WebPart {
<#
.Synopsis
   Short description
.DESCRIPTION
   Does not work, it redirects
.EXAMPLE
   Example of how to use this cmdlet
.EXAMPLE
   Another example of how to use this cmdlet
#>
    [CmdletBinding()]
    Param
    ([Parameter(Mandatory=$true)]$PageUrl,
    [Parameter(Mandatory=$true)]$WebPartTitle)
    asnp *share*
    $site = new-object microsoft.sharepoint.spsite $PageUrl
    $web = $site.OpenWeb()
    $wpManager = $web.GetLimitedWebPartManager($PageUrl, [System.Web.UI.WebControls.WebParts.PersonalizationScope]::Shared)
    $webpart = $wpManager.WebParts | ? { $_.Title -eq $WebPartTitle }
    if (-not $webpart) { throw "No webpart with the provided Title was found" }
    $url = "$($web.Url)/_vti_bin/exportwp.aspx?pageurl=$PageUrl&guidstring=$($webpart.ID)"
    $wc = new-object net.webclient
    $wc.UseDefaultCredentials = $true
    $content = $wc.DownloadString($url)

    # another alternative
    $IE = New-Object -com internetexplorer.application; 
    $IE.visible = $true; 
    $IE.navigate($url); 
    
    #another alternative
    [net.httpwebrequest]$s = [net.webrequest]::Create($url)
    $s.AllowAutoRedirect = $true
    $s.UseDefaultCredentials = $true
    $response = $s.GetResponse()

}