Apple TV 1st Generation: disassembling procedure

Apple TV 1st Generation – Disassembling procedure – How to remove the bottom cover – How to remove the power supply – How to replace the Hard disk

Flip the Apple TV over so that the bottom of the unit is facing up.
You need to remove the rubber base to get access to the screws.
Starting at one side of the device, use a hairdryer or a heat gun to soften the adhesive holding the rubber base in place.
The rubber base will be hot after heating, take extreme caution while proceeding to avoid personal injury.
While the adhesive is still warm, peel the bottom of the rubber base upwards to detach it from the metal plate.
Repeat the procedure described above until the rubber base has been completely removed.

Remove the four T10 Torx screws that secure the lower case to the upper case.

Carefully lift the lower case from the upper case enough to allow access to the internals of the Apple TV.

Be aware that the hard drive is physically attached to the lower case and that a ribbon cable runs from the drive to the logic board in the upper case.

Carefully pull the hard drive data cable straight up from its socket on the logic board. During reassembly, make sure the hard drive data cable is firmly seated in its socket on the logic board; otherwise, during boot-up you will see a flashing question mark "?".

Pry the AirPort antenna cables straight up from their sockets on the logic board.

Remove the single T8 Torx screw securing the AirPort card to the logic board.

Cautiously lift the AirPort card and pull it straight away. Slide it from its socket on the logic board.

POWER SUPPLY REMOVAL

 Disconnect the power cable straight up from its socket on the logic board.

There is a release tab that must be pushed inwards in conjunction with pulling to release the power cable
Make sure to pull the connector traight up from its socket and not toward the face of the logic board.

Remove the following three screws securing the power supply to the upper case:
One 4.8 mm T8 Torx screw
Two 5.8 mm T8 Torx screws

Use your finger to push and dislodge the AC power connector inwards, towards the power supply.This should pop out easily.

How to remove Hard Drive

Carefully pull the hard drive data cable straight up from its socket on the logic board. During reassembly, make sure the hard drive data cable is firmly seated in its socket on the logic board; otherwise, during boot-up you will see a flashing question mark "?".

Remove the four T8 Torx screws securing the hard drive to the lower case.

Align the new hard drive with the screw holes on the lower case.

While holding the hard drive in place, insert and tighten the screws back into the lower case.
Don't forget to reconnect the hard drive data cable to its socket on the logic board.