Take the display enclosure and, if it's necessary, remove the dirt using a brush and a vacuum cleaner. Isopropyl alcohol would work well too but do not use it nearby the wifi antennas which are on the top right corner.

Take the new display and turn it down on the enclosure starting from the bottom, as it is shown in pic#2. Once all of the pins which stand nearby the screws' threads have passed through the metal tabs, the display is correctly positioned.

The webcam cable goes behind the display tab.

Finally secure the new display to its enclosure remounting the four Phillips PM2.0×2.9 screws using a PH#00 screwdriver.