This is peeling because the homeowner not only didn't prime over the existing paint, they tried to paint a gloss over a gloss without sanding the first layer down a bit.
The first problem to deal with is the glossy finish. Gently scuff up the surface of the paint with some fine sandpaper.
I highly recommend using a pole sander to get this job done more efficiently and in a lot less time than if you were doing it by hand.
Once you've scuffed the entire surface, wipe it with a damp microfiber cloth to remove all of the dust and residue.
Once the wall is clean and dry you need to prime the surface with a good quality primer. This is especially important when you're trying to fix up a bad paint job. The primer coat will even out the base surface and help the new paint to adhere to the wall.
Once the primer coat is completely dry you can recoat the wall with some fresh paint. These critical prep steps are the key to a good finish!! I'm Mrs. Fixit and it's just that simple!
