Just as Microsoft has the Windows 10 Insider program to allow us to get the latest Windows 10 features that are in preview, the Office team has a similar program.

If you have a Personal Office subscription, you can go into any Office 2016/365 app and go to File -> Account and click the Insider option.

For commercial/corporate, this may not be available as it’s controlled by the installation done by the IT department.

For IT Admins who want to get the Office Insider for themselves, developers, testers, etc. the process is easy.

1. Uninstall previous Office versions and reboot on any system prior to installing the Insider.
2. Download the Office Deployment Toolkit
3. Extract the Setup.exe and Configuration.xml file into it’s own directory.

4. Edit the Configuration.xml with notepad or your favorite text editor to read as below

<Configuration>
 <Add OfficeClientEdition="32" Channel="InsiderFast">
   <Product ID="O365ProPlusRetail">
    <Language ID="en-us" />
   </Product>
  </Add> 
</Configuration>

5. from an elevated prompt, run Setup.exe /configure configuration.xml 

6.  After the installation is complete, open an Office app, such as Word, and go to File >          Account. Under the Product Information section, you should see text that includes              “Office Insider.”