Open Word or Excel
Open a blank document
Click on “File”, “Options”, “Save”, and check “Save to Computer by default” as shown below and click “OK” at the bottom of that window to save the setting:
If you have an alternate location you may want to change the “Default local file location as well” such as a network my documents redirected path mapping.
Now the next time you click “save as” you will notice it now goes to “This PC” rather than OneDrive: