See above.  Yes, it's technically possible - but it's like replacing the screen on a cell phone.  The odds of breaking the outer glass when removing it are very, very high - meaning you'll wind up having to replace the entire unit anyway.  And even if you CAN get it apart, you then have to glue the assembly back together without creating a mess. Translation:  if you've done it before and are certain you know exactly what you're doing, you may get it to work.  Practically speaking, replace the entire assembly.  Odds are very high that's exactly what you'll wind up doing in the end anyway, either for aesthetic reasons or because you break the very flimsy outer glass in trying to pry it apart. These assemblies are put together by a robot on an assembly line -- they're not designed to be easily repaired by human hands.  
I have an inspiron 7559 with the UHD touchscreen. I suspect the screen is cracked, it's leaking LCD fluid and starting to fuzz out. I want to replace it with a FHD screen but would like to know if I need to replace the entire LCD assembly or just a FHD screen replacement is required.   Reason for asking is to clarify what was mentioned in this other post,  "The UHD screen resolution is 3840 x 2160 and comes only with a touchscreen. You would need to change the entire LCD assembly." [URL]
Inspiron 7559 screen replacement