Installing Grasshopper Plugins

Via Powershell command

[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://docs.itau.uni-weimar.de/attachments/14'))

By extracting manually

Download the Zip Archive and extract the contents into %Appdata%\Grasshopper\Libraries.