Since this is an all-in-one design, there's no soldering required, but there are a few extra hacker-ports for those interested in tweaking!
If for some reason you want to read/edit the EDID EEPROM, the top left has 4 pins: +5V, GND, SCL and SDA. The EEPROM can be written to with some Arduino code here
The backlight driver can be dimmed with a PWM signal. Use ~1KHz or so to dim/adjust the backlight. You can use 3V or 5V logic for the PWM signal. The monitor does not have the ability to do its own dimming, you'll need a seperate computer/microcontroller pin to do that.
If you want to save power, you can drop the backlight current.
On the 5" model you can adjust the backlight from 50mA down to 25mA by cutting the trace in between the two pads labeled Open for -25mA, if you put a switch between those pads you can switch on the fly between half and full brightness
On the 7" model the default backlight is 150mA and you can adjust it down by cutting any of the solder jumpers marked -25mA or -50mA
You may want to 'recycle' the 5V or 3V power from the board, we supply two power pads for the USB 5V power and the 3.3V regulated power. This is different than the +5V HDMI power which is used for powering the EEPROM and isn't good for current draw.