You dont have to do any of this!!!
All i did (JUST reinstalled my mac from a 250 to 1TB WOOO!) is use time machine.
Use your snow leapard cd. and when you are installing point to time machine on your external drive. I ordered a 2nd TB drive for a customer, and used it to back up my 250. THen i threw the 2nd tb drive in my pc, named it during the SL install, pointed to leapard and about 230 gb took 3.5 hours to come back. BUT everything is here! All my updates, games, Photoshop, even all of my favorites in safari and chrome. all my mail is back and it is on the update i left off on! Apple made it sound much more difficult.
"lion network install" is only available on brand new models, and i dont want to spend 10 more dollars because mac wont sell a cd for lion, my install dmg was long gone, and when i logged in appstore, lion showed up as 30 bucks again, not installed.
I gave time machine a shot and it worked fine..bottom line
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i used the SL cd to re install and you dont have to even go into app store. lion directly installed back on, just use your time machine. ^^^Makes that post waaaay shorter.