The Gameboy Color in Teal!
The only tool and technique you will need to open this is a small flathead screwdriver and, well… screw driving skills. There is some finagling with the external screws, but you can get it! It’s pretty simple and compact in there!
On that note: Two interesting things! One, It’s super compact with lots of hard soldering on the inside. I point this out because I think it’s a huge factor in what makes it feel like a simple object on the outside, molded to closely contain everything inside. The other is what you will later see int he buttons. They’re just silicone rubber and molded plastic! I was hoping to find some button I could appropriate, but instead, just little nubbins! But I suppose this was done to save on damageable parts and space, making the contact points directly in the fiberglass board. Anyway, read on! It’s kinda neat how simple it appears on a large scale, but how complicated it is on the board.
My guess is the casing you see is injection molded. Flip it over and look at the back.
You’ll have to remove these ridiculous tri-wing screws with a tiny flathead if you can’t get a tri-wing driver in a timely manner. That’s what I did. You have to jimmy them around until they slowly turn with the weak torque you can provide. (P.S. My gameboy was missing it’s battery case. I used aluminum tape for years… AA batteries.)
Pop the case off!
Then this plate from the back side that holds the game steady in the access point with four phillips head screws. Plate appears to be stainless. All the screws look like galvanized steel. Three on the interior may be brass. But it is unclear
Now look at the fiberglass circuit board.
It’s held into place by three phillips screws. These are the ones that may be brass. Pull those out and you can pull out the board and flip it! Note: At the top of the board is the connection point for the game cartridge.
Before you remove the board, detach the LCD screen. There are little black switches to pop out on either side of that red tape. Then just pull out the tab.
Board removed:
This reveals the active side of the speaker that plays MIDI tones in the bottom right hand of the board, and the underside of the buttons on the face of the gameboy. 
Also removable is the cover of the power button and the infrared sensor cover.
Power Switch
Infrared on right, power indicator in red LED at top.
Power switch and LED covers both present on the side of the object (left to right).
The black dots on the back of the buttons appear to be magnets or something conductive to make contact with these components in the white portion of the board.
Here too is the volume knob.
You can remove the LCD screen with a black foam padding on the back by prying it lightly with anything flat and sturdy with rounded edges (so as not to damage the thin steel casing). I used a really old flathead screwdriver that wasn’t sharp at all.
The LCD Screen. That’s the last part to remove!
Other parts on the board include a lot of hard soldered stuff.
This includes an optical inverter (right), the CPU (center), regulated power supply module (top left), SHARP chip of some identifiable kind based on number (center left), and an integrated circuit (bottom right).
And here it is all exploded and knolled!
Thanks for looking!
-Will-