This has all happened before, and it will happen again...
I think you're a bit mixed up.
The "Final Five" & the other members of the 13th Tribe on Earth were humanoid Cylons, and had come from Kobol (where they had originally been created by humans).
Two thousand years ago, the Final Five (& the rest of the 13th Tribe) died in the nuclear holocaust on Earth (started by Centurions they'd made themselves on Earth?).
The Five though were resurrected on a ship in orbit. They slowly travelled back to the Colonies, to warn the other 12 Tribes about the dangers of artificial life, but were too late - when they arrived (the time of the 12 Colonies' first Cylon war), the humans of the 12 Colonies had already created Cylon Centurions (with the first work done by Daniel Graystone in the "Caprica" series), which had rebelled against their creators.
The Final Five did a deal with the Centurions: the Centurions would end the war against the Colonies, & the Five would help them evolve by creating humanoid Cylons (the 8 models of "skinjob") plus would give them resurrection technology. [The Centurions had already been experimenting with hybrids, but had not managed to make humanoid Cylons]
The first of the "skinjobs" made by the Five was John (Brother Cavil). They then made the others, including one model called "Daniel", which John/Cavil killed completely.
John/Cavil then rebelled against his creators, killing them & then imprisoning their resurrected selves, followed by implanting false memories in them & dumping them in the Colonies so they could witness his upcoming nuclear holocaust on the 12 Colonies.
LOL, I had to keep pausing the episode everytime something was revealed, so I could absorb it & think back to earlier episodes. So many revelations in this episode!
I think though we still need more detail on...
What exactly happened on Earth 2000 years ago? I think it's at least been implied it was a Centurion rebellion there too.
What happened on Kobol to cause the various Tribes to leave?
When were the 13th created?
What happened to the original Centurions the Colonials made? What did they do & where did they go once the Five had made the Skinjobs?
and probably more things I can't quite think of at the moment