Redo Setup Assistant on OSX Lion

I upgraded to a Macbook Pro today and they had me run through setup assistant in the store.

I came home to use Migration Assistant with my Time Machine drive to load my settings, files and applications. Now when I run time machine, it wants to backup everything that it loaded again, along with backing up my entire external hard drive again.

After searching, I've heard this problem doesn't occur if you setup your files via Setup Assistant instead of Migration Assistant, so now I'm trying to see if there is a way I can run Setup Assistant again.

Any help is appreciated!!

That's the way Time Machine is supposed to work. You used the correct procedure to migrate. Time Machine migration works best and is easy.

Erase your external hard drive with Disk Utility, format it as HFS Extended Journaled and start your Time Machine backups again. The first backup will take the longest. Why would you want to run the setup assistant again?

I don't see why I would need to erase my external drive.

My Time Machine drive wants to backup 350GB of data when all of that is duplicate. I would think that after using Migration Assistant to restore your old settings and files, there would be an option to continue with incremental changes in Time Machine, instead of Time Machine wanting to backup exactly what I just copied from it two hours prior.

And ditto for my external drive. I use Time Machine to back this up and now it wants to back this up again given the computer change.

That's why I thought Setup Assistant would circumvent these issues, and would link the new Macbook with the old Time Machine backups. I read Migration Assistant doesn't do the same thing.