I know you already know some of this, but please bear with me.
When you hit Menu on the remote, the screen should first show the ‘Video in proc’ category. From here, you would use the up and down directional buttons to select a category, then enter it with the OK button. As with the categories, you would use up and down to select a setting, and then you would use the left and right buttons to reconfigure that setting. Pressing the Exit button will get you back out to the categories list, and pressing the Menu button will exit the menu regardless of where you are in the navigation.