Delete a frame (and content)
1) Select the frame by left-clicking on it with a mouse
2) Hit the Delete button in the small pop-up menu
This will remove the frame from the path, including all the content inside it.
Delete frame and keep content
You can also only delete the frame and still keep all the content:. For this you should:
1) Right-click on the frame
2) Click on “Remove Frame without Deleting Content”