You can no longer delete your BowerKits. Instead, you should 'archive' them from your Dashboard.
Click on the three dots below your BowerKit thumbnail.
From the dropdown menu, click Archive.
Once archived, your BowerKit will no longer show on Discover or on your profiles. You can unarchive your BowerKit by heading here or clicking the 'filter icon' at the top of your Dashboard:
If for some reason you need to fully delete a BowerKit, please contact support.