How to restore Macbook Pro to factory settings

I have searched and searched and all posts say to hit option, repartition the dirve to one partition and restore from disks.

THAT does not work when Apple no longer gives you the disks and the retore is on a seperate partition. Setting it to one partition would wipe out my capability to restore to factory settings.

Unfortunately, this question has to be asked again for new macbook pro users. How do I restore to factory settings using the on board restore system with no disks supplied at purchase?

Thank You.