Why not just splice the cable? Why would you need to open it?

It's machine pressed together when manufactured. This is so the is no chance a consumer can "accidentally" open and become harmed from the high voltage inside. I would just buy a new adapter. Even if you manage to open the adapter you raise the risk of a potential fire 10 fold. I really wouldn't attempt this unless you are VERY familiar with high voltage circuitry. I don't mean to discourage, but just make sure you understand the risks involved.

Best of luck!

-Varsity

I've actually opened one of these adapters before- it's pretty difficult. You'll need a hammer and screwdriver/chisel to get the thing started. Just tap around the edges, and eventually the thing will crack. Be advised that you can in fact zap yourself (I did it multiple times), but there isn't really enough juice in there to hurt you, unless you leave the adapter plugged into a source of power.

It's really pretty difficult to fix any of the internals- everything is so tightly wedged together that you'll have a hard time getting things replaced. At any rate, if you're going to do any work on it, you should make sure you're good with electronic circuitry.