Offline plug-in installation process Follow

1) Open http://resharper-plugins.jetbrains.com/packages in a browser;

2) Log in to a site;

3) Find a plugin e.g. http://resharper-plugins.jetbrains.com/packages/JetBrains.AngularJS/ (pay attention, that there may be two versions of a plugin - one for R# 8.x and one for R# 10.x/2016.x);

4) In Version History, select a plugin version which covers installed R# build; 

5) If you logged in, there will be a Download link;

6) Hit Download link and download the nuget package;

Note: If there are any additional dependencies (apart from "Wave") in Dependencies section on a plugin's page, download and put them to a local folder as well;

7) Put it to any local folder;

8) Specify such folder here "ReSharper | Options | Environment | Extension Manager | Add" and uncheck ".NET Products Gallery" checkbox;

9) Run ReSharper | Extension Manager and install the plugin which appears there.

Hint: if you use IE11 and it downloads *.zip file instead of *.nupkg, just change the file extension from "zip" to "nupkg".