I have some .nupkg files from a C# book. How can I install them?
![Can't see my packages][(https://i.sstatic.net/RMgIm.jpg)
Menu Tools → Options → Package Manager
Give a name and folder location. Click OK. Drop your NuGet package files in that folder.
Go to your Project in Solution Explorer, right click and select "Manage NuGet Packages". Select your new package source.
Here is the documentation.