Step 1. You need to access the archived board page by clicking on “Show archived board” choose the option “Yes”.
Step 2. Now open the archived board you want to delete.
Step 3. Click on the clockwork icon (settings)
Step 4. Now choose the “Delete board” option
Final Step. After clicking on the “Delete board” option you’re going to see a message saying “Are you sure you want to delete the board?”
You need to confirm by clicking on the check button that says “I want to delete this board and all its messages, this action cannot be reverted.”
Now click on the “Yes, delete it!” button.