My screen cracked, how to open the case to replace the screen?

Hi

I have a Call Mynah Bluetooth Call Recorder, more info here:

Website

The screen cracked, and i can't figure out how to open the case in order to find the screen part number and try to replace it.

There is no screws at all on the case, i tried pulling the back/front with a suction cup with no success either.

Following pictures of case:

Image 1

Image 2

Thanks.