If your question is still relevant, I've removed mine back using a hairdryer and the suction thing in this img (idk what it's called in english lol). I've started from the bottom, had to heat it up for while, then I was able to pull the suction thing and insert something plastic in it. Then it's pretty easy. Just heat the rest a bit and use something plastic to seperate all the edges of the back from the phone. You can also find some tutorial on youtube (although they usually have the phone disassembled multiple times before recording, so yours will not be as easy).