The only way of fixing a cracked laptop screen is replacing it. To do so, first disconnect the laptop from the power source, and remove its battery. Next, remove the screen bezel, take out the cracked screen, install the replacement screen, and then reinstall the screen bezel. Use your laptop's model number to purchase a compatible replacement screen.
If you see rubber cushions after removing the bezel, remove the cushions, and remove the screws beneath the cushions. Use a thin metal blade to pop any of the corners loose, and work your way around the bezel using a plastic spudger until the bezel is completely detached.
With the bezel off, the screen's mounting brackets should be visible. Remove the screws securing the mounting brackets to the lid, rest the cracked screen on a flat surface, and disconnect the cable connected to it. If there are any additional cables, disconnect them as well.
Connect the cables you just detached from the old screen to the replacement screen, carefully position the screen in the lid, and secure it using the appropriate screws. Reconnect the battery, and turn the laptop on. If the new screen works well, fix the rubber cushions, reattach the bezel, and tightly close the remaining external screws.