HP OEM vl420 vs ASUS P4B-MX

Recommended by Wim's BIOS...

If possible, what way would be the the surest
approach to attempt a re flash of a HP motherboard,
the HP is a vl 420mt, which is based on an ASUS P4B-MX
intel 845i board. The issue here is that the hp OEM
board comes with an AMI bios, and is likely soldered on,
while the original ASUS comes with AWARD Bios.
Both BIOS'es uses some hardware lock, at this point not sure
how they are disabled, and if it matters.
I might attempt uniflash, unless eg awdflash or asus flasher
can be used? tia.