ECS Liva PC bios/boot logo

I'd like to replace the bios/boot logo on my liva pci.

I've got the choice of two bios files from here



http://download.ecs.com.tw/dlfileecs/BIOSROM/liva/50211MNK-System.zip
http://download.ecs.com.tw/dlfileecs/BIOSROM/liva/50123MNK-System.zip


I'm using a Mac apart from the liva pc so I'm a little limited on what tools are available.

I've downloaded and installed UEFI tool but not sure what to do next. The last time I played with bios logos it was on a VIA EPIA M1000 so a good few years ago.