Remove the back cover of your Nokia Lumia 820

When inserting the SIM card, or if you want to replace the regular back cover with the wireless charging shell, avoid damaging your new phone - only use your fingers when opening the back cover.

At the top right corner, put your thumbnail in the seam between the screen frame and the back cover, and bend the cover until it opens slightly. Then do the same on the left side, and bend the cover open.