2 - 4 Stunden
I wantd an SSD system disc and one hdd for pictures and music. Apple would only sell me one or the other.
Taking the mac mini apart was easy. The hard part was putting it all back together again.
Check the orientation of the power cable to the motherboard when dismantling the computer. Make sure that the old hd is flush with the power supply before putting the motherboard back in - get those power cables out of the way. The hardest part was getting all the screws for the airport antenna to line up right - i did it using more force than should be necessary.