Read the complete discription and watch the video before you try it!
Toothpaste (not gel toothpaste)
Something 100% cotton
A slightly damp clean paper towel or something.
Put a little toothpaste on the 100% cotton and lightly apply to the smartphone in a circular motion.
Let it sit for about 15 mins or something.
Take the slightly damp clean paper towel (or anything that's slightly damp that will not leave residue) and wipe down the screen.
Maybe do it again if needed.
Important: use damp towel on step 4 or it will scratch even more! Also use real toothpaste not gel toothpaste! And wipe lightly when applying or more scratches! And finally don't get toothpaste in any of the port holes!