It should not be necessary to do anything: both the items and the snippets should be immediately available.
My guess is that there must be something different about your Visual Studio set-up / configuration, and I'd like to figure out what it is.
First, let's figure out if the NakedObjects.Ide Nuget package did install the items and snippets. You should be able to check this in the trace in Output window, selecting the Package Manager option (imediately after the install). If not,
go look in the right directories. The items should be in e.g:
...\Documents\Visual Studio 2010\Templates\ItemTemplates\Visual C#\Naked Objects
and the code snippets in e.g.:
...\Documents\Visual Studio 2010\Code Snippets\Visual C#\Naked Objects
Can you first confirm that they are there. If they are then we need to figure out why VS isn't picking them up automatically.