Open the page by clicking on the thumbnail of the page on the Pages tab (assuming you have a Tribute open). On the Page Edit view you will see a button in the top right hand corner that reads "Delete." Click that to delete the page. You will be asked to confirm your preference.

There is no way to un-do this action, so be careful deleting pages (especially those submitted by others to a tribute you are organizing). Remember, an organizer has editorial rights for the pages, so you can edit the text or swap out the picture instead of deleting a page, if you'd rather.