How to sperate the screen from the touch

@augustinekobba they are fused together. Can it be done? Yes, but it is not easy and requires some tools and consumable that cost plenty more than a complete display assembly. Take a look at this video how it would be done right. You most likely do not have those tools. You would need a hot plate, to heat the screen, then you would have to try to separate the glass/digitizer from the display (some thin molybdenum wire can possibly slice it). IMHO that is the most difficult part. Let's say you got this done, you would then need to adhere the new glass to the display. For that you need LOCA/OCA glue. You will need to have a vacuum source to ensure your glass seats properly and without any bubbles between the glass and display. There are many steps in between but it gives you an idea of how involved a repair like this really is. You can also check this video where it is shown how to remove the Glass.

Best of luck with your repair and do let us know how it works out for you.