While it’s certainly doable for anyone with a modicum of technical expertise (and written for that audience), one can only wonder about average users (for whom it could be argued that Jean François Champollion had an easier time deciphering Egyptian hieroglyphics).
6. Complete the baseband downgrade by jailbreaking/activating, installing SSH on to the iPhone etc. There are tons of wiki's about that so I won't repeat. (Probably also true for step 4 and 5.)
7. Extract the baseband firmware and EEPROM files of 3.14 from the ramdisk of firmware 1.0.2. The files are named ICE03.14.08_G.eep and ICE03.14.08_G.fls and are located under /usr/local/standalone/firmware.
8. Get the secpack of baseband firmware 4.0 (some people have that, I have no idea how they got it but its needed). Name it "secpack". (maybe http://**********.com/files/61914114/secpack40113.bin will help)
9. Download iEraser2 here or from Geohot's blog.
10. Install all the tools onto the iPhone (I use the location /usr/local/bin.) You need to have SSH access to the 1.0.2 firmware iPhone and upload iEraser2, the secpack, ICE03.14.08_G.eep, ICE03.14.08_G.fls and anySIM 1.0.2
This is ludicrous. Apple, please figure out a way, tacitly or explicitly, to unlock the damned phone so people can get on with things — and please stop bricking phones. Your contract with AT&T is not nearly as important as your goodwill and market opportunity.