I couldn't figure out how to get that band thingy detached either! I just did my soldering in car (such a rebel
But if you're careful, you can get the board off. Just pull out the black plastic cover infront of it, you'll notice a hole in the middle (roughly lined up with the fan speed dial). If you move it slightly, the board pulls off.
From here, you just have to turn the bulb a 1/2 turn and it pulls out.
You can get any color led at an electronics shop too.
but bulbs are way easier.
hope that explains it a little.