Just did the replacement of Optidrive with my original HDD (which I had earlier replaced with a Samsung EVO 500 GB drive - using ifixit's method). I omitted steps 6,7,8 and 11. The upper left side screw of the OptiDrive is deeply placed - a magnetic screwdriver with a long thin shaft would be essential to remove and especially, to replace it.
Just did the replacement of Optidrive with my original HDD (which I had earlier replaced with a Samsung EVO 500 GB drive - using ifixit's method). I omitted steps 6,7,8 and 11. The upper left side screw of the OptiDrive is deeply placed - a magnetic screwdriver with a long thin shaft would be essential to remove and especially, to replace it.