The backlid is easily removed since the SD card and the two SIM cards need to be placed here.

It's the one covering the battery. It has written the model name, color, lot number, and IMEI numbers and barcodes.

Unscrew the 12 visible screws You know, with the usual almost universal screwdriver

Unscrew the top right covered screw This one is covered by a white round plastic patch (in the white version of this phone): it's probably a warranty patch. You can simply put the screwdriver on it, push a little and unscrew the underneath screw.

Starting from the top you can detatch the plastic frame. I stopped when I got to the bottom part (the one with the micro-USB charging port).

...ANY HELP HERE?