Clean OS X install guide - questions

Hi everyone,
This is my first post so please bear with me on this one as I don't understand several things from the clean OS X install guide I've just read.

Ok..., I purchased a brand new 2011 MBA, i5 CPU, 4GB RAM, 128 SDD with Lion installed.
I want to format the drive and install a clean MAC OS X on the SSD.

What do I do?
You are mentioning that you need to have a bootable Lion DVD but how do I make one?
You are also mentioning to download the .dmg file from the App Store but this is silly because I bought Mac with Lion? Do I have to pay for it once more?

What do you mean by MAC OS DVD #1 and #2?
So #1 is Leopard and #2 is Lion?
Do I need to install Leopard first and then Lion?

As I understand Lion fits on a single layer DVD so it should be one DVD, right?

Thanks!

blevins321 said:

This. Your MBA has a clean install on there already..no extra software. To get iLife, open the App Store and you'll see them appear in your purchased items (they're free for you). In the future to reinstall, hold down Apple+R during boot to go to recovery mode. That will allow you to download a new copy of Lion onto your laptop.

Click to expand...

OK, I understand now. Thank you!