Can't unpack bios rom from exe. (Samsung Ativ 4)

I have Samsung Ativ 4.
I updated my bios from P01RBG to P08RBG. Unfortunately after update my SSD can't reach SATA3 speeds. It is limited to SATA2, regardless of BIOS settings.

I want to downgrade my bios.

I found version P06RBG, but I can't unpack it. Could you help me?
http://sbuservice.samsungmobile.com/uplo...P06RBG.exe