Now I want to try mod the old maps, but I need some questions answering first, please

When I install dvd2xbox, can I do it by a memory card (action replay) or do I have to FTP it? If I can memory card it which game do I use?
When I get dvd2xbox, do I have to make it my main dashboard? so that when I turn on the xbox it will automatically appear instead of the original one?
Is there anywhere to get halo 2 onto my hdd using dvd2xbox but without actually making it my dashboard?
If I have to make it my dash, how to I delete it and restore the original dash when I have modded the old maps?
Thanks alot, my main concern is if i must make dvd2xbox my dashboard, how to I restore it to the original?