How to replace the hard disk of Apple Mack Mini

HARD DISK REPLACEMENT PROCEDURE 

Place your thumbs in the depressions cut into the bottom cover. Rotate the bottom cover counter-clockwise until the white dot painted on the bottom cover is aligned with the ring inscribed on the outer case.
You do not need to apply much downward pressure while turning.

Tilt the mini enough to allow the bottom cover to fall away from the outer case. Remove the bottom cover and set it aside.

Remove the two 11.3 mm T6 Torx screws securing the fan to the logic board near the antenna plate.

Lift the ear of the fan nearest the RAM up off the standoff secured to the outer case. Removing the standoff screw is not necessary to remove the fan. You need only raise the fan enough to lift it off the standoff screw.

Lift the fan out of the mini for enough clearance to access its connector. Carefully pull the fan cables upward to lift the fan connector up out of its socket on the logic board. Remove the fan.

Remove the single 3.5 mm T6 Torx crew securing the cowling to the heat sink.

Lift the cowling from the end nearest the antenna plate. Rotate the cowling away from the outer case and remove it from the mini.

Remove the following screws securing the antenna plate to the mini:

Two 6.6 mm T8 Torx screws Two 5.0 mm T8 Torx or 2.0 mm Hex screws (either screwdriver will work)
W hen putting back together: It can be difficult to get the hard drive seated correctly such that the antenna plate fits in place correctly. If the screw holes don't line up with those on the hard drive, make sure that the two pins that are in the back of the hard drive are properly seated in the holes at the back of the case, above the housing for the second hard drive. The antenna attaches directly to the hard drive (red markers), therefore attaching the antenna can move the hard drive around and loosen the connection of the hard drive cable to the logic board.

Slightly lift the antenna plate from the end closest to the RAM. Carefully pull the antenna plate away from the circular rim of the outer case.

Do not remove the antenna plate yet. It is still attached to the AirPort/ Bluetooth board.

Use the tip of a spudger to carefully pry the antenna connector up from its socket on the AirPort/Bluetooth board.

Remove the antenna plate from the mini.

Use the flat end of a spudger to pry the hard drive connector up from its socket on the logic board.

Use the tip of a spudger to lift the IR sensor connector up and out of its socket on the logic board.

Remove the following three screws: One 5.0 mm T8 Torx or 2.0 mm Hex screw (either screwdriver will work)
One 16.2 mm T6 Torx screw
One 26 mm T6 Torx standoff

To remove the logic board, the two cylindrical rods of the Mac Mini Logic Board Removal Tool must be inserted into the holes highlighted in red. Inserting instruments into any logic board holes other than the ones highlighted in red may destroy the logic board.

Insert the Mac Mini Logic Board Removal Tool into the two holes highlighted in red. Be sure it makes contact with the top side of outer case below the logic board before proceeding.
Carefully pull the tool toward the I/O board. The logic board and I/O board assembly should slightly slide out of the outer case.
Cease prying when the I/O board is visibly separated from the outer case.
Remove the Mac Mini Logic Board Removal tool.

Simultaneously push the two plastic clips on the far left and right sides of the I/O board toward the middle of the I/O board and pull the I/O board away from the outer case. Only pull the logic board assembly out of the outer case until the edge of the I/O board is about .5" away from the edge of the aluminum outer case.

Pull the hard drive away from the front edge of the mini and remove it from the outer case.

Remove the strip of tape connecting the hard drive cable to the hard drive. Remove the hard drive cable by pulling its connector straight away from the hard drive.

Remove the two 6.2 mm T8 Torx screws from the side of the hard drive. Carefully peel the hard drive cover off the hard drive. Hard drive remains.