As much as I appreciate IFixIt guides this one falls short of their usual high standard.
There are several omissions that can lead to a failed repair.
I wanted to say much more but it would not fit on this page, so briefly:
Failed to mention importance of opening system to determine original brand of drive installed (Seagate, Western Digital, Samsung).
Failed to mention need to get same brand so that thermal sensor could be attached to new drive.
Failed to mention without thermal sensor attached fan will continuously run at full speed very loudly.
Failed to mention need to trim off polarization tab from thermal sensor connector on Western Digital drives.
Failed to mention need to trim 8 pin thermal sensor block on Western Digital drives down to 6 pins so that sensor can be flipped yet keep thermal sensor wires connected to the second set of pins closest to the SATA connector.
Failed to mention that lifting the LCD slowly as cables can be glued in place and need to be freed up or risk damaging.