Repair peeling wall

My wall looks like it does in the pictures. What steps are necessary to make it uniformly white without it peeling off?

Wrong color on wrong background.

Wrong color on the wrong background.

What steps are necessary to make them uniformly white without flaking off?

You need to remove the old stuff. Then see what the substrate is. It might be worth removing everything and re-plastering or re-wallpapering. If that is not feasible because you don’t have the time for it, then scrape some of the substrate off and take it to the paint specialist store (not the hardware store!). They will advise you regarding a suitable primer.

So I would be for getting rid of it. ;) Remove the wallpaper, re-wallpaper, and paint. It seems to me there is already a lot of paint on it.

Well, I'd be for it. ;) Remove the wallpaper, re-wallpaper and paint. It seems to me there’s already a lot of paint on it.

...nothing soaks in anymore either ;)