How Can I Copy or Install Games on Xbox 360 Without Using the Disk?

Hello all…please I need help. I just purchased my Xbox 360 with a HDD of 20GB and I was thinking of copying or installing games onto my console via my USB or external HDD. Please I want to know if I need to get a special software to be able to play the games or install the games on it or I can just copy them on my console and play it.

Suggestion:

Can't be done legally and we don't/can't talk about illegal ways. Buy or rent the games and play them the right way.