If its really dead, there are no way to remove it. However if its stuck pixel u can try those apps in play store. Most of the time it doesn't help much. Other tricks involves applying pressure on the stuck pixel by pressing it physically with your finger. I personally cured stuck pixel on 2 of my devices by snapping (jentik) the stuck pixel with varied strength. You can search Google for more examples how to apply pressure on the stuck pixel. Good luck

Dead pixel is exclusively black. Stuck pixel comes in many colors including black.

Try to apply pressure on it and see if there are any reaction to it. If no reaction at all, then can safely consider it as dead