Step 1: simply clean your screen by utilizing the wet cloth, and dry with the green fabric.
Step 2: open the bottle and remove the gray rubber completely.
Step 3: pour fair amount of liquid to cover the surface (you most likely will end up with extra liquid so why not using it on the camera lens and the back "if its glass" or on another phone).
Step 4: spread the liquid using the dry cloth and wait 30 seconds.