To delete a Collection from your site, first click Collection under Widgets in the My Apps menu.
There are two methods to delete a collection.
Click details to the left of the collection you would like to delete.
At the Collection Details screen, click Edit this Collection.
In the Edit Collection window, click Delete in the top right corner.
Clicking delete causes a window to pop up to confirm that you want to delete the collection. Note: once an item is deleted it cannot be restored.
At the Collections screen, click the checkbox to the left of the collection you would like to delete. Multiple checkboxes can be selected at once.
Click delete above the list of collections.
Clicking the delete link will cause a window to pop up, confirming that you want to delete the collection(s). Note: once it is deleted, it cannot be restored.