2. Moisten (not dripping) a soft piece of lint-free cloth with Isopropyl Alcohol (rubbing alcohol). You can use pure ethanol (70%) but I prefer isopropyl alcohol because of its quick drying properties.
3. Softly rub the display with the cloth.
Warning: Never apply much pressure to anywhere, where a stubborn thing is stuck. You might kill the pixels of your display, resulting in stuck or dead pixels. Rub repeatedly over the place, but never hard.