Click HERE on creating a new gallery section to any page.
Select the Gallery section you’re adding photos to from the sidebar.
Alternatively, you can just click on the Gallery section straight:
To ADD an image to your Gallery,
Scroll down until you see the Media thumbnails.
Hit 'Add new media':
You can then upload a file from your Desktop. Be sure to fill up the Display Text field too!
Once that's done, click the 'Add item' button.
After which, it should appear in your gallery.
To REMOVE an image,
Scroll down until you see the Media thumbnails. Click the 'X' button to remove that particular image
Alternatively, you can also add back the image by clicking on 'Add existing media'. This is especially so if you deleted an image by accident.
A drop-down menu will appear and you can restore the image back.
To REPLACE an existing image in the gallery,
Click on the row you'd want to replace.
You can click 'Upload A New File' and select the image you'd like from your Desktop. This will replace the image that was previously there.