You cannot hack xbox.com, now or ever. They're s*** is encrypted. The only thing that might happen is a glitch in their system. The reason you can download the Halo 3 Beta is because it's still on the xbox servers and it never cost money, so it's technically free. Why haven't they removed it? Why would they, you can't use it anyways. There's no way getting around this. Just get a code or get money to buy it.
It is in fact all server side. Proof of this is that if you sign into Halo 3 offline, you will have an empty service record and when you sign into XBL, the service record is downloaded. So, no, you can't.
I love how you try to attack me and fail horribly. What makes you think I made that changer program or had anything to do with it? All I did was supply offset and values, he did whatever because I don't think it actually required an app.