Downgrade iPhone Baseband 04.12.01 to 01.59.00

I found this video:

This is the definitive method to downgrade the baseband of your iPhone.
We can do the downgrade of the baseband 01.59.00 (with iPhone 4 baseband 04.12.01, 04.11.08, 4.10.01, 3.10.01, 2.10.04)