I don't know this device, However I can give you some general advice on opening cases.
Arm yourself with the following tools.
A tooth pick, two slim bladed small electrical type screwdrivers, A broader bladed screwdriver, a small torch and a hobby knife.
Explore all the joins, being as delicate as you can insert the small screwdriver or failing that the hobby knife and lever apart slightly. Using the torch, look for any clips or other means that are holding the thing together. Often the front or back is the 'snap on' type and you can see the clips and lever them aside to release the panel. At that point you may find some screws. Either way once you can see your way forward you may be able to separate the parts using a combination of leverage with the screwdrivers and blade. Sometimes any little plastic clips will break as you get it to come apart. If you don't break too many you will be able to re-assemble it. Failing that you will have to use tape to keep it all together again.
Look very hard at any labels. Probe gently with the tooth pick to see if there is a screw hiding underneath. If you suspect here is, remove the label.