You can skip this step if you bought your putty knife from iFixit. Putty knives purchased from iFixit come with pre-ground edges.

You'll need a putty knife in order to open the case. A 1.5 inch thin putty knife will work well, but you'll want to grind the edge down. Rub the putty knife's short edge back and forth on a sheet of all purpose rough grit sandpaper (100 grit will work fine) until it attains a beveled edge.

Place the mini upside down on a cloth and turn it so that the apple leaf faces you.

Insert the putty knife into the seam between silver outer case and the white plastic. If you have trouble, you can insert the putty knife at an angle or grind the knife's edge down further. Push the blade down until you meet firm resistance (roughly 3/8 of an inch).

Pull directly back on the putty knife until the white plastics pops up. Don't worry about bending the putty knife too far or breaking the plastic tabs. Just continue to pull back on the putty knife until the case pops free.

Repeat this procedure on the other side.

Grasp the white lower case beneath the vent and rotate it up and away from you, pulling it free of the upper case.

If your mini does not have Airport installed, then skip this step.

Grasp the Airport antenna board and lift it off of the two plastic posts holding it in place. You may need to push back the black plastic tab jutting through the lower left corner of the board.

Remove the yellow tape securing the power button cable to the black plastic framework.

Remove the three black Phillips screws securing the plastic framework to the logic board and lower case.

Grasp the optical drive and mass storage unit in one hand and lift up enough so that you can see beneath it.