Importing gallery images from classic

When I import my class site into Elements it works well in terms of all the pages structure and resources. However, pages using the Gallery 3 stack have imported all the empty images stacks. I want to remove them and start with an Elements Gallery component. I am unable to select one of the empty classic stacks at a time in order to make the page empty and it is laborious to choose them one by one as there are many images on the site. How can I delete them all easily?

Delete the page and start fresh??

Alternatively, try select all on the page and delete

I guess deleting the page is the best we can do. Select all doesn’t work with this situation. Thanks.