Image Editing (using GIMP)
GIMP is available at https://www.gimp.org/downloads/
UPDATES:
If you are missing the dialogs for your tools and layers, you can restore them from the Windows menu.
You can paste automatically to a new layer by opening the Edit menu and selecting "Paste as", then "New Layer".
00:36 Rotating
01:05 Cropping
01:30 Resizing
01:55 De-skewing
02:25 Using layers (injecting someone into a photo)
02:56 Magic wand
05:58 Erasing
07:05 Using Gaussian blur
07:20 Saving changes
07:42 Exporting image (includes flattening image)
08:24 Fixing flaws (using clone and heal tools)
09:31 Replacing colour
09:39 Magic want (again)
10:46 Adjusting levels