Install / Upgrade Fedora using 2 USB flash drive

Well my friend have a problem upgrading his Fedora laptop, to make
bootable flash drive using the dvd image needed size more than 8 GB,
so he told me how he did it with 2 4GB flash drives. Being a student,
well sometimes there are items we just rather use things that are
laying around than buying. So he has one 4GB and borrowed another 4GB
flash drive from his friend.

so we have 2 USB flash drive, both is 4GB
simply the idea is make a small bootable flash drive using boot.iso
and when booting we point the image to the other flash drive.

where do i get the boot.iso image?
well go to any mirror and paste this at the end
"/releases/16/Fedora/i386/os/images/" and of course, do change 16 and
i386 if you are feeling that this is already outdated.

use unetbootin to make a bootable flash drive using boot.iso and make
sure boot.iso from the version you are upgrading.

put the dvd image in the other flash drive.

so, you have 2 flash drive, one is the bootable flash drive with the
boot.iso image and one is the fedora dvd image

boot from flash drive and at the Select Partition part(something that
looks like this http://wiki.amahi.org/index.php/File:F14usb-s4.png),
find your fedora dvd image from the other flash drive and continue
installing / upgrading.