I accidentally upgraded my 3gs to bb 5.16.02, os 4.3.2. I think the original os was 3.x.

Is it still possible to downgrade it to 5.13.04, 4.0/4.0.2/4.0.3 which is unlockable by Ultrasn0w?

It doesn't matter if I will loose all my files in it. All that matters is downgrade it.

Please advise.