How can I open and edit Office files on my Google Chromebook?

Here is guidance from support at Google:

On your Chromebook, you can open, edit, download, and convert many Microsoft® Office files, such as Word, PowerPoint, or Excel files.

Important: Before you edit Office files, check that your Chromebook software is up to date.

Option 1: Edit Office files on your Chromebook

You can edit most Microsoft® Office files on your Chromebook without installing any other apps.

  1. If you haven’t yet, download the Office file to your Chromebook.
  2. In the corner of your screen, click the Launcher   Up arrow .
  3. Find your file, and double-click it to open.
  4. Edit your file.

Note: Some features and settings won’t work unless you save your file as a Google Docs, Sheets, or Slides file.

Option 2: Edit Office files online

If you have a Microsoft® Office online account, you can edit your files in Chrome using these extensions and apps:

Work together on a file with others

You can share Office files with others and work together to edit the file in real time:

  1. Edit your Office file.
  2. Save your file as Google Docs, Sheets, or Slides.
  3. Share your file, then begin working with others.

Note: Any updates made to the Google Docs, Sheets, or Slides file will not carry over to the original Office file.

https://support.google.com/chromebook/answer/2481498?hl=en&visit_id=636761674804653977-3884614084&rd=1