for flashing a hitachi 78fk you will need to put the drive in mode_b using the mode_b utility in dos
so than it can be recognised in windows. use toolbox from maximus to update the firmware.
flashing a sammy ms25 or 28 youll have to create a bootdisk (by example iprep) to boot in dos so you can read, dump, copy
and write the custom firmware.

u can also use toolbox from maximus but you wil have to connect youre 360
on a pc tht has a sata controller

i bought a 360 elite on ebay with a red light error code 0020, and i fixed it by doing the x-clamp replacement fix. the system was working fine for about 3 months and just as i was playing at tht time the screen frooze and had to shut it down, after i turned it back on the 3 red light error appeard again and showed me the error 0102 wich had to be a bad bga solder, wich results in a poor connection to the gpu.  Ive repaird about 30 360s and almost everyone of them at first were overheating in gpu and somtimes in the cpu and know more of those 360s are sufferin from these errors.

There are many many fix tutorials on the internet tht might help you get your xbox up and running again but sadly  all of them are just temporarly, ive tried reflowing the solders, but tht helped me for only a week or so. the second time i did it the 3 lights came back even faster (i think 99% of all systems will eventually get this error, couse of the constant change in temparature in the solder all because off MS bad ventilation and poor bga soldering.

Doing the x-clamp fix and by simply putting in a 12v fan might helps your system for a while but its not sure how long tht might last couse of its bad bga soldering even if you modify the casing and mount extra fans it will only add a few months or years at the most (like lots off people who might have tried these options as there last hope) the main board might still react a little causing the bga's to disconnect (cold solder joint) (0102) memory failure; one of the most common failures besides overheating.

i have done a fix myself  tht has made my xbox working perfectly again for 3 weeks, 5 hours in a row every day  .
To apply this fix 1st off all i had to find out how the memory modules are attached couse they dont have legs but instead are solderd underneath the chip (BGA), wich most xboxes suffer from is a bad bga solder.
one way is too resolder (reballing) the memory models to the mainboard, (using more or better solder). you can do tht by using an infrared soldermachine or some kind of special solder tool wich by the way are  way too expensive and i wont even consider spending more money on this piece of $#!t machine and who knows what might happen next.

so here is the cheap way;  the trick is to perform some pressure on the bga solders of ALL 8 RAMMODULES to keep contact with the GPU so you wont get a poor connection (cold solder joint)

1.dismantle your xbox, find a guide on internet if you dont know how
2.take everything apart but you can leave de cpus heatsink on for now. reflow de bga's on your main board (gpu, rammodules) by using a heatgun or anythyng else tht can produce up to 200 degrees celsius air, anyway find a guide anywere. (IMPORTANT; AFTER REFLOWING LET THE SYSTEM COOL DOWN FOR 30MIN OR YOU MIGHT RISK SQUASHING THE BGAS)
2.do the x-clamp replacemant fix, youll need: thermal paste(as5 or any), 8 m5 screws(flathead so you wont need to drill your case anyway otherwise is fine by me) 16metal m5 rings, 16 nylon/teflon rings. find a guide on internet if needed.
3.you need 4 pieces of normal rubber 4mmhigh, 11mmwide and 14mmlong for underneath the 4 chips. figure out where they would face in the metal casing underneath and glue them there, tht will give you the pressure for underneath when you tighten up the screws.
4.this for the above chips; cut of an old piece of heatsink tht will exactly fit on top of the 2 chips tht are still visable with the exact hight of the gpus sink. put a small amount of thermal paste underneath the just made heatsink and on top of the 2 chips, as for now you will need to fill the top of the made heatsink with some soft stuf like rubber tape, (thts what i used) or a piece of sponge, tht so when the dvd drive sits on top of it with the case closed it will build the pressure on the 2 chips.
4.now for the 2 chips under the gpu heatsink youll need 2 metal rings both 1.75mm thick (i used 2 25 cent coins wich is about 1.75mm) (this needs too be almost exact in order the build up enough pressure both on the chips and the gpu and tht it wont break anything) figure out where they should face under the gpu heatsink and attach them ther with some thermal tape, make sure tht the coins are fully covered.
5.youre now ready to put everything back in place, just be careful when tighting up the screws to evenly tighten up.

am not sure this fix will help on any xbox but am pretty sure on most off them, couse its workin for me fine since. altough am not too sure how long this might last, i think ill just keep on testing and let you guys know what happens. If requested i can put some pictures online of my modded xbox to give some guide on how to perform this fix (pressure fix) NOTE: DONT TRY THIS IF YOU DONT NO WHAT YOURE DOING OR RISK BREAKING ANY SENSITIVE PARTS LEAVING YOURE CONSOLE USELESS.

Anyways good luck, if you got nothing to loose this might be the only cheap permanent fix for know, the only thing you will need to worry about after this fix is its ventilation.