While lifting the screen up with one iPod opening tool, insert a second iPod opening tool in between the outer case and the top left edge of the glass panel.
Remove the first iPod opening tool from between the glass and LCD in the top of the device.
Prying up slightly on the iPod opening tool, insert a second iPod opening tool in between the front glass and the outer case, on the right side of the screen.
Slide the second iPod opening tool along the right edge of the panel to remove the adhesive.
With one iPod opening tool still between the glass and outer case, insert a second iPod opening tool in between the front glass and outer case, on the left side.
Slide the second iPod opening tool toward the bottom of the device to remove the adhesive.
Lift the click wheel out of the way with one hand and use a plastic opening tool to pry the click wheel ribbon cable connector off its socket on the logic board.
Use a heat gun to soften the adhesive underneath the camera/microphone cover.
Pry the camera/microphone cover off the case with a metal spudger and remove it.
It is extremely difficult, if not impossible, to avoid damaging the iPod case near the camera. While this will not affect the iPod's functionality, it will hurt its cosmetic appearance.
You can try this alternative method for removing the cover:
Use a hot glue gun to apply a bead of glue across the cover.
Move the nozzle in the glue for 20 seconds to heat the lens adhesive holding the lens in place.
Press a spudger into the hot glue and hold it in place until the glue cools and hardens.
Pull on the spudger with firm steady force, while using a fingernail to pry on the cover edge.
Continue to push the logic board assembly through the outer case of the iPod with a spudger.
Tolerances inside the Nano are extremely tight. Be very patient and go slowly when removing the logic board assembly, and make sure no components or ribbon cables get caught on the case.
To make sure that the hold switch plate does not catch on the housing of the iPod and tear the cable, feed the switch straight down the center of the device, where the opening is the widest.
at step 14 when lifting the click wheel have a look at the small black bar, placed to the upper edge of the chip. in its center it holds a very small tiny coil spring thats hardly to see and that easily jumps out. better you lift the click wheel in parallel to the ground. if spring jumps off one time, you will never find it again. i guess it has some grounding purpose a it docks on the metal below the logic on the click wheel. also a point to have an eye on at reassembly