A bit of homework/research never hurt anyone. Google is your best friend.
That aside, here's how it works. For Samsung, BenQ and Toshiba drives, all you need is a SATA cable and JungleFlasher, Iprep, DosFlasher, or whatever other flasher tools are available. Google tutorials to find/use them and where to find the right firmwares (like iXtreme). They're pretty easy to do.
For LiteOn, it all depends on what version you have. IIRC, A0A2 would be LiteOn 7 series, the same as mine, and easily the more common of the LiteOns. LiteOn 7 doesn't like letting us see its key, or even accessing it with a computer, so you need a little bit of kit to connect to it. This is the connectivity kit, the most popular 2 being CK3 Pro and Maximus. You also need a probe/spear that pokes a particular hole in the LiteOn PCB (board for putting chips in) in order to even enable it to dump its key - this is why LiteOn 7s are annoying to flash. The kit usually costs around £30, with another £11 for the probe/spear.
The kit used to use serial only, but now it comes with USB - you just need to download and install the drivers before even trying.
If you're lucky, you'll have a LiteOn 8 series. Clever people have found a "back hole" for flashing it so you don't need the probe/spear, although you still need the kit, from what I've read. However there is also a big thread in the xbox scene about LiteOn 8 drives that do not dump the key (I hear these are mostly exclusively elites or xboxes that have been repaired by M$). These are generally the newest ones, used in some xboxs after July '09. Check the back of your Xbox to see when it was made.
I've also read that flashing LiteOns can be dangerous for the drive. If you don't disable the laser before flashing, there's a chance the laser might become bricked. If that happens, then it's easiest to grab a spare drive/laser from ebay to switch the lasers around - I hear BenQ or LiteOn lasers work (LiteOn I hear was developed by BenQ and Phillips too).
I've read a lot of tutorials and things around the whole flashing process so I'm pretty confident I can do it right if I had all the parts, but if you're not so confident then it really is best to try and find a pro to do it for you. There are many all over the place, just have to find them. Or you can try asking nicely for another 'temper to do it for you, although that purely depends on who reads it, where they are located, and if they are kind enough to do it for you.
Oh, and remember that M$ CAN detect flashed firmwares, so the risk of banning is always there. It's also much more likely if you play games not yet released in your region, or games that haven't been properly "stealthed", or badly dumped games, or games on bad media/been burned badly. And while I'm at it, you can only use DVD+R DL media (Verbatim is best). If you're still confident, good luck (and wish me luck too with getting mine flashed)
