First Step : A simple reminder on Ribbon and Ribbon Workbench

What is it?

First, we must distinguish two different things:

• The Ribbon is an element of the CRM. It basically displays the action bar with several action buttons following on the page the user is working on. Its main goal is to provide easily and very quickly all the actions possible according the user context navigation. The other advantage is its responsivity. It automatically adapts each menu depending on the context. 
   
• The Ribbon Workbench for CRM is a tool developed by Scott Durow in order to have a control on the Ribbon. The main advantage is its adaptability on each screens and situation encountered throughout the user experience. It is indeed very easy to add or remove elements from a menu according to the current entity, thanks to a very user-friendly drag and drop system. Moreover, this tool also replace the complex XML manipulations and simplify the Ribbon modification for user with a fully graphic interface.

The installation

You must first download and install the RWB solution from the official web site.

Then, the application RWB is accessible by clicking on the RWB button present in Dynamics 365 and Go to Settings -> Customizations -> Solutions. 

Before to start to use the app, you must create a new unmanaged solution with everything’s required on your context of ribbon manipulations. 

Then you can run the app and select the newly created solution and you should see all the artifact needed. 

The possibilities

You can modify or create new items on menus. There are two types of ribbon :

The Application Ribbons: This is the menu presents in the entire system. Typically, if we want to add a button on the global app ribbon (next to search for example), it is the type of ribbon we will have to use.

The Individual Entity Ribbons: These menus are linked to a specific entity. For instance, if we only want to add a button in on the contact creation form.
Three types of individual entity ribbons:

• Homegrid – This is the entity home page, means the one that displays the list of records with the view selector. 
• Form – The is the ribbon that appears into an entity form
• SubGrid – This is the ribbon that appears into a linked entity displayed on a specific record form.

Full tutorial : 

You can follow the very detailed official tutorial : https://ribbonworkbench.uservoice.com/knowledgebase/articles/71374-1-getting-started-with-the-ribbon-workbench