While it's not possible to remove or uninstall Briefing, you can disable the app completely in your Apps manager.

Disable the Briefing app:

1. Open your device Settings

2. Locate Briefing from your list of app (select All apps or Show system apps if you don't see it)

3. Tap Disable, then confirm

What does it mean to disable Briefing?

Because Briefing is a system app, disabling it will not free up its space. Disabling Briefing, however, will prevent it from using system resources as well as further auto-updates from occurring. In addition, this will revert your version of the Briefing app to the factory one.