For updating a forked branch on Github or any other git related system. First you need to clone your forked branch on your local machine because there is no any one click updater solution.

First clone

 

Get into cloned folder

 

Add a Remote Upstream and Fetch everything

 

Pull this new version onto your old forked branch;

 

Now you can check the version on your local repository with; (I assume there is a version file to read)

 

Push everything into your remote Git repository;

 

Done.