A few issues... How to 'unattach' an image from a page. How to change the order of appearance of images in the gallery template on a page.
1.Go to the Edit Page (Pages -> All Pages -> Your Page) in the dashboard, delete that image from the text editor if present there and then click on the add media button above the top left of the text editor section . 2. Select the "Uploaded to this page" from the combo box list and then select the images that you want to remove from the page and then delete them from the attachment details section present in the right side. 3. Close the window from the top right of this page and update it. For this issue. 1. Go to the Gallery Edit Page (Pages -> All Pages -> Your Gallery Page) in the dashboard and click on add media button above the top left of the text editor section. 2. Select the "Uploaded to this page" from the combo box list and here you can change the order of the images by draging and putting them in according to your sequence. 3 Close the window from the top right of this page It will solve your issue.