This is actually a very quick process. I suggest using the XBOX 360 Transfer Cable Kit, which you can buy at any gaming retail store, such as Gamestop and Walmart. To use the Transfer Kit, you must still have the old hard drive that contains your profile
and game saves.
Here is the process for using the XBOX 360 Transfer Cable Kit:
1) Turn off your current XBOX 360 Console.
2) Make sure you have the old hard drive removed from the old console.
3) Connect the transfer cable to the old hard drive, then plug it into one of the USB ports in the front of the new console.
4) Turn on the new console. If you have the most recent software update for the XBOX 360, you will see a message pop up. It will read: "Transfer cable detected. Do you want to transfer content now?"
5) Choose "Yes, transfer to console."
6) Select "Start" to begin the transfer.
If you have any DLC, there is an extra process you will need to go through to be able to use the downloaded content and games on the new console. Here it is:
1) Sign into XBOX Live on your XBOX Live Profile.
2) Go to the Settings tab on the Dashboard.
3) Go to Your Billing Options, and then select License Transfer.
4) Follow the on-screen instructions to finish the process.