How to download/export the .wsp files in sharepoint 2007

Download the powershell form this link:  https://www.microsoft.com/en-us/download/details.aspx?id=20020

Then follow the below steps with power shell.

1) [Void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint")

2) $farm = [microsoft.sharepoint.administration.spfarm]::Local

3) $wsp = $farm.Solutions.Item(“ToolbarManager.wsp“).SolutionFile

4) $wsp.SaveAs(“c:\ ToolbarManager.wsp “)