A. 1. Open Google Calendar on a web browser, as the mobile app does not support bulk deletion. 2. Use the 'Agenda' view to see all events listed. 3. Hold down the 'Ctrl' key (or 'Command' on Mac) and click on each event you want to delete. 4. Once selected, click on the trash can icon to delete them all at once.

B. 1. If you need to delete recurring events, open one of the events, select 'Delete', and choose 'All events' to remove the entire series.