How do you open the battery compartment of a Reddmango MP3?

I also bought my Reddmango MP3 Player from Argos. BIG MISTAKE!! Not Argos mind,...just the MP3 Player!!Not only is the instruction guide virtually useless, I am also having trouble trying to download music, and trying to check whether successful. I can't open it the damn thing. A). Its hard to tell whether the MP3 Player is switched on or off. B). Whether in lock or unlock position. C). And, as for trying to open said MP3 Player to insert battery? Forget it!!

Think I will stick to my Ipod Nano, which I also have. Much simpler. Just bought the Reddmango on a whim, to use whilst working out.

Reddmango? What a con?

Very annoyed!!