Applying a design package to a large number of site collections can be a tedious task. To expedite the process, we can use PowerShell. In this recipe, we are going to use a PowerShell script (PS1) to upload and apply a design package to each content site collection in each web application on the local SharePoint farm.
Follow these steps to import a design package to all site collections with PowerShell:
Microsoft.SharePoint.Publishing.dllassemblies into the PowerShell session.
[Reflection.Assembly]::LoadFrom("C:\Program Files\Common Files\microsoft shared\Web Server ...