How do I enable/disable Lumin as the default PDF viewer from my Google Drive?

When you connect the Lumin app to Google Drive, you can select Lumin as your default viewer for easy viewing and annotation of PDF documents.

Enabling as Default: 

1. First, ensure you have installed the Lumin app on your Google Drive. Find out how here.
2. Go to your Google Drive.
3. Click Settings.
   
   
   
4. Click Manage Apps.
5. Find Lumin.
6. Next to the Lumin app, tick the box for Use by default.
   

Disabling as Default: 

To disable Lumin as the default app, follow the above steps and ensure that in Step 5 the box is unticked.