This extension to NuGet Package Explorer allows you to quickly open dll's from the package into ILSpy, without the need to extract the package, go into explorer, and open it up manually.
To install the plugin, just open up NuGet Package Explorer
and select Tools > Plugin Manager...
Add the downloaded library
in the list of loaded plugins and you're good to go.
Just double click an assembly inside an NuGet package and it will prompt you to open it in ILSpy.
Of course you need to have ILSpy
on your computer (as well as NuGet Package Explorer
1.5 or above).