Resmed S7 Lightweight - Change settings

I've searched and been unable to find out how to change my pressure settings on my Resmed S7 Lightweight. Can anyone help?
Thanks!

Here's my limited knowledge: Hope it helps.

- Turn machine ON.
- Hold down the DOWN ARROW BUTTON AND THE RED BUTTON on the right at the same time for a few seconds until CLINICAL MENU shows in the screen.
- Push GREEN BUTTON on left under the word MENU. Use up/down arrows to navigate from there. There is a setting for CPAP where you can change the pressure. Just be sure to note what settings were so if they get changed inadvertently you can change them back.

QUESTION: What I don't know is what the setting of Pressure Gain is for. When the CPAP pressure is changed, Pressure Gain changes too. Pressure Gain can be increased but couldn't get it to decrease. Maybe someone else can tell you that.

Thank you so much!!! I've been looking for this information!!!