To be safe, just buy this.
http://www.newegg.com/Product/Product.aspx...N82E16815124022
All you do is open up your 360, you don't need to take it apart. Then you attach the DVD cable to this card, and flash the firmware.
"Costs
You will most likely have to spend a good amount of money in order to do this. Flashing the Xbox 360 firmware usually requires a specific SATA chipset, so if you don’t have a SATA chipset that is compatible for flashing your drive, you have to purchase a compatible PCI Sata card. Many people purchase the VIA VT6421 PCI SATA cards that usually cost around $20 USD. That is just for flashing the drive. In order to make game backups you need something to rip them with and something to burn them. First, let’s skip to burning. You’re going to need a DVD burner that can burn Double Layer DVD+R DL discs. You may also want to look into seeing if your burner supports something called “bitsetting” to DVD-ROM. A cheap, quality drive that automatically bitsets for you is the Pioneer 112D. You can find these online for around $40 USD. A burner isn’t going to do you any good without discs to burn them to. So get some DVD+R DL. My recommendation: use Verbatim brand discs, as they are the highest quality and you will not suffer from read errors if they are burned correctly. These discs, at the cheapest, will set you back around $2 USD a disc.
You may already have some of these, but if you have none of them, you’re looking at quite a bit of money. $20 USD for a SATA card, $40 USD for a burner, $40 USD for some DVD+R DL (assuming you want to backup 20 games). You have to ask yourself if it is worth it or not."