Haven't actually taken it apart, but the sides feel loose. Try inserting a thin flat blade screwdriver (or guitar pick, if you have one), in the crack, and prying it gently open. Works for many/most electronics these days. The key is that there are indentations and corresponding teeth placed around that joint, so just go slow, and you should be able to open it without damage.
I had the same issue with the cable breaking internally. Twice in fact. Nokia eventually replaced the second one. The first I tried dismantling. The two screws are a decoy. The top and bottom halfs are actually welded together and you can only get inside by levering/smashing it apart.
If you carry the charger about with you alot this will keep happening. I bought the dedicated travel charger and have since had no further problems.
Mine's the AC-4U (US?) I assume 4E is european? In any case, mine has one small Torx screw, and does indeed pop apart very easily once the screw is out.
when I contacted Nokia they said that accessories only have a 6 month warranty.
Accessories? I don't call it an accessory if it comes packaged with the device, and you need it in order to get the device to work. However, they're not expensive to replace. Unfortunately, the UK Nokia site shows them as 'out of stock' at the moment.
