First, get the right tools. A T6 (Torx) screw driver and a good, clean pair of tweezers. (also try to get a heat gun and a case opening tool to separate the screen from the plastic frame - not pictured here)
Then, proceed to remove the back and the battery
You will see 7 screws at this point, and the eighth will be covered by a small white sticker with the word "void" on it. Mine doesn't show it for obvious reasons . Remove these screws using the screw driver that you got before.
Now, you will need to release 3 plastic latches (one on the top and two on the sides). Be very careful as they are rather easy to break.
Once you are done, you should be able to separate the inner casing from the phone/screen/motherboard assembly.
In here, you will see the vibrating motor and its connection to the motherboard. To remove it, simply take out the connector. However, you must be careful as the cables for the connector are thin and fragile. A pair of tweezers is recommended for this step, but make sure that you pull the plastic connector and not the cables themselves.
This picture also revealed anaother T6 screw (remove it) as well as one of the water damage indicators (HTC added two of these suckers and hid them well).
If you look at the bottom of the device, you will see the second water indicator as well as another T6 screw (remove it as well).
Now, this pic is not part of the guide itself but based on the discoveries on the Sensation and EVo 3D about the download mode connectors, I believe that these two may be the same, probably to put the device in service/download mode... would be interesting to try this out sometime (bootloader re-write/downgrade possible?)
Ok, back to the guide... Now, you will see that the cables connecting both ends of the motherboard are safely held by plastic holders/latches. On top of that, you will also see latches for the top part of the mother board (one on each side). Carefully, free the connecting cables are the motherboard from these latches. You could use a part of tweezers for the cables
Now comes one of the more delicate parts of the process. You will need to disconnect the two ribbon data cables from the motherboard connectors. These can easily break, and they both control touch ON THE ENTIRE FACE OF THE DEVICE, so extreme care must be used here. These can and will break if you are not careful enough or if you pull them too hard.
And this is where I messed up . There are two very small ribbon cables that connect the buttons to the motherboard. The one on the side is the one for the volume rockers and the top one is the one for the power button. Thinking that it was just a piece of tape (as it is covered in black tape) I pulled it out and broke it. DO NOT DO THAT!!! Same goes for the top one.
The screen itself is what must be removed first before attempting to separate the motherboard from the plastic shell. The connectors for the physical buttons will simply not allow you to do this easily. Moreover, the entire thing is actually glued in place (buttons and screen), so you will need a heat gun and a case opening tool to separate the screen from the housing itself, avoiding damage to the device (like I did)
Well, there you have it folks. Hopefully insight of the innards of this device can yield a bit more to develop on this great and rather sturdy device. Thanks for reading.