Based on the image, I believe you have the 5" PanelDue. The manufacturer sells online (from China), however not the full PanelDue (pcb with display), so depending on your capabilities, replacing the display panel alone, might not always be a viable option (most probably to not compete with Duet3D). But if you want to attempt, here is what you need:
The 5" panel is the one at https://www.buydisplay.com/5-tft-lcd-display-module-wvga-800x480-high-resolution-for-mp4-gps
I would suggest buying it with the Resistive Touch Panel included (no need for the ZIF connector).
The display is glued to the PanelDue pcb - I am not sure with what, but that will need to be removed, cleaned and somehow the new panel should be re-attached to the board, in the correct location. The ribbon cable is simply reconnected with its connector on the pcb.
When removing the old display and handling the new one, make sure that you are careful - the touch panel is very sensitive, and even a slight bend, can break it. My old touch panel broke into many small pieces while removing it from the display. Even a very small crack on the touch panel, renders it useless.