Just to repeat my comment from step 4: you do not dismantle everything. Once the 8 Torx 10 screws from the LCD plate are untightend, the LCD plate can be lifted a few centimeters (or inches). It’s limited by the cables but the opening angle is wide enough to untighten the two hard disk bracket screws (Torx 9), to unplug the two SATA connectors and to lift out the hard disk. You need either someone holding the LCD, a third arm or anything soft like a towel or the leftover of a kitchenroll which has to be stuffed between the logic boards and the LCD plate to hold it.

Auf Deutsch: Man braucht keine Kabel zu lösen. Einfach das LCD-Display anheben, am Ende die Papprolle aus einer Küchenrolle, ein Handtuch oder Schal reinstopfen, damit das Display so bleibt und man kann die zwei Schrauben für die HD-Halteklammer so lösen, wenn man einen Schraubendreher hat, der nicht zu lang ist. Die Festplatte bekommt man leicht heraus.

The harddisk can be removed WITHOUT the next steps. The opening angle of the partially lifted LCD display gives enough room to untighten the two Torx T9 screws of the hard disk bracket, to unplug the two SATA connectors and to carefully lift out the harddisk. There is absolutely no need to dismantle the whole thing.

All you need is a screwdriver which fits into the room. I’ve used the “Pro Tech Toolkit” from iFixit. The screwdriver with Torx T9 bit fits perfectly.

The other “tool” you need is either someone who holds the LCD plate or the inner leftover of a kitchenroll, a scrunched paper, a small towel or similar which has to be stuffed between the logic boards and the LCD plate to keep the LCD at its lifted place (careful! don’t unplug any of the cables).

I’ve opened and changed the harddisks of those 21,5 iMacs a dozen times with the help of the “Pro Tech Toolkit” and a kitchen roll.

Hmm… yes, the magnets sucks - literally. But if you use a normal screwdriver or a bit, the screwdriver tip or the bit can be “loaded” by the magnets too. Just move the screwdriver (or bit) over one of the magnets and then “plug” the screw onto the screwdriver’s tip (or bit). It will be held by magnetic force. Just enough to move the screw vertically and very slowly into the whole.

There are some special screwdriver on the market with “claws” to hold screws, but they are hard to find/to buy and expensive. I sometimes use superglue (a LITTLE) to temporary fasten the screw at the screwdrivers tip. This technique can be used with destroyed screw heads too to optimize adhesion.