REMaster Plus Humidifier adjustments

How do I adjust my humidity level? I understand that there are 5 levels. My current level leaves my mouth and nose feeling dry and cottony.

The left top-most button has an up-arrow on it. Pressing and holding that button should increase you humidity level. The LCD display should then show the new humidity setting (1 through 5).

The left bottom-most button with the down arrow can be used to decrease your humidity level.