Getting a new macbook pro, and selling my old one- how do I "factory reset"

I want to do a clean install of Lion on my current (old) macbook pro before I buy a new one. How do I do this? I can't seem to find a straight answer.

I can't buy the new one until I sell this one, so I have to have it clean and "factory fresh" and not have any of my data on it. I already have a backup on an external firewire 800 disk, which I will use to import my stuff to on the new computer.

If I re-download Lion from the app store, will it give me a clean, fresh install?
Or is there another way to do this?

Pretty much I just want to nuke my old computer and have a clean Lion copy on it with no data

thanks

whiteonline said:

Legally, you can only sell the computer with the original OS installed. Since your sig lists a 2008, use the DVD media and reinstall.
Lion in the app store is tied to your iTunes account.

If you are selling a machine that came with Lion preinstalled, perform the internet recovery to reinstall.

Click to expand...

It came with Leopard pre-installed. I lost the disc a long time ago.

T5BRICK said:

If the buyer tries to reinstall the OS in the future, they won't be able to unless they buy it.

Your computer doesn't support Internet recovery, but you can boot from the restore partition and do the same thing. Just use disk utility from the recovery partition to delete your data and reinstall the OS from there.

Click to expand...

Yeah, I expect them to upgrade to 10.8 sometime in the future.

But wait, you've lost me there- I know that the computer is too old for Internet Recovery- but what do you mean by restore partition/recovery partition?

I probably sound retarded right now. I am sure there is an easy way to do this, used computers get sold all the time

T5BRICK said:

When you installed 10.7, it created a restore partition automatically(as long as everything went right during the install).

Restart your computer and hold down command + R. It should boot from the restore partition and you can go from there.

http://support.apple.com/kb/HT4718

Click to expand...

Oh reeeaallllly?
well, I will surely be trying this.