Reinstalling MacOS but need to backup to Google Drive before Clearing your disk? Here is how to do it…
Step 1: Go to Recovery Mode (Cmd + R) [https://support.apple.com/en-in/HT201255]
Step 2: Click on ‘Safari’ Browse Apple Support to get help with your Mac.

Step 3: Open a new tab by (Cmd + T).
Step 4: Browse to your Google Drive Account.
Step 5: Click on folder upload and backup your data here.
Author is a Senior Software Engineer with a graduation (engineering) in Information Technology.
Disclaimer: Author does not claim the method and is not responsible for any ill happenings. Do it at your own risk.