Should be a screw for the lock to take off. Well since you did all that, I got to ask did you break the door panal?

Now Im not at any lock or anything right now
So my memory is a little fuzzy

But if I were you just start looking at it and figureing it out, its the best way to learn anything, most of the time! Anyways the lock is already broken, so dont wory about breaking the lock (unless you think you can fix the lock), most of the time people come into these forums and its usally some kind of spring thing, anyways japanies should of done a little better on the door locks!