In order to complete the removal of the SharePoint social features on SharePoint Server 2013 and deploy the Yammer integration, you will also need to register a custom Cascading Style Sheet (CSS) file and add it to your master pages. The exact details of this process aren't required for the exam, but you do need to know that this process is required.

If you have configured a custom master page for My Sites, you can simply add or create the custom CSS file and reference it in your custom master page. If you are using the out-of-the-box master page, you will need to deploy a SharePoint solution using Visual Studio.

You can learn more about this process at https://docs.microsoft.com/en-us/SharePoint/administration/hide-sharepoint-server-social-features#sharepoint-server-2013.