If flashbios runs on your console the easiest thing to do is just network flash via that. No need to burn flash discs, no need to rename the bios file.. Instructions here:
http://www.team-xecuter.com/flashbios/
Now.. if you do want to use cromwell and eurasia to flash you can do that.. I'll go through and answer your questions on that...
QUOTE(proconsoles @ Aug 24 2006, 06:45 AM)

do I need to put the DuoX2 switch on Bank 0 OR bank 1 ?????
If you want to use a set of eurasia flash discs then you need to boot to cromwell (bank0). For all machines that boot flashbios though (That is all 1.0-1.4 and some, but not all 1.6s) it's easier to just flash from flashbios.
QUOTE
Do I need to write bios.txt and raincoat.cfg to the disc ??
For a Eurasia bios disc, you should, yes.
QUOTE
x2config file Do I really need this file ?
Yes and no.. without the file your xbox will just boot to the default config. To customize bios options (Colors, LBA48 options, IGR, live blocking, dashboard location, etc) you should have the file on E:. It also will boot your console a few seconds faster if the file is present.
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So for 1.0 - 1.5 I need to rename "x2_5035_vOLD_512k.bin" to bios.bin and put it in the bios_disc dir.
So for v1.6 and v1.6b I need to rename "x2_5035_v16plus_512k.bin" to bios.bin and put it in the bios_disc dir. Am I right ?
Correct.
QUOTE
When the "EurAsia Pro Generic Flash Disc v1.2 disc" asks me to put in the "X2 BIOS Build 5035 disc", do I then need to put the switch from BANK 0 -> BANK 1 ????
No, but you can. If you slide the switch over prior to flashing you'll flash over the other bank so that you can always come back to the other bank to reflash if you need to. (This usually makes more sense if you flash with flashbios.. or if you have a 1.6 where flashbios doesn't load).