In the Visual Studio main menu, click on Tools->NuGet Package Manager->Package Manager Console. A window will appear at the bottom of your screen.
In this window at the PM> prompt type: cd C:\BpTitanium\Bps.Titanium.Database.Base
You can type dir at the prompt any time to check what folder you are in.
Then type: .\Bps.Titanium.Database.Base.Schema\PackageManagerIntegration\Init.ps1
Once this is run you will be able to run the commands defined in Init.ps1 in the Package Manager Console window.