K-750i - changing the firmware

Hi guys!

I'd like to change the firmware of my SE K750i from

R1AA008 version to the last official (stable!) release (I think is the
R1BC002) through

SEUS (I hope to eliminate the noises during the calls).

Before starting, however, I'd like to know if it's possible (and how?) to
reinstall the preceding version of the firmware if something went badly
after the upgrade.

Do U recommend to proceed in the upgrade even if the new firmware seems not
to read the m4a files? (which files are these?!)

Thanks in advance



Here's my current firmware:



R1AA008

prgCXC125952_EU_1_CL

R1AA008



Version SW LCD

Current: 0



Version SW

camera

Current: 4.5



Version SW ITP

CXC 125 932 R1K



Personalizations:

CDA102338/58 R4A

cxc 125953 R1AA008

EUROPE_5



Content version:

PA19