Updating bios to motherboard

Hello all, I need some help please. I have a older desktop computer with a ASUS P5GC-MX/1333 motherboard and I had to change the motherboard battery for it was not keeping good time and date and the bios reverted back to the default bios. I guess I need to update the bios and I have never done that before. I have tried to follow ASUS’ES directions to update the bios and I guess i just don’t get it I guess, I am sorry to say. I was not able to even find the updated version of the bios which after 2 hours of trying I was not able to get it right or find the information that I needed. I am not a geek, but do the best that I can. I am using Mint 22 cinnamon 64 bit and this computer is 64 bit and if i can update the bios, it might be a little quicker in some processes. Any help is much appreciated. I do not know what other information that someone might need, but just let me know and I will try to get it. Thank you very much, Porkgrinder

With a bit of luck your device manufacturer may publish its hardware updates on LVFS. Check it out:
https://fwupd.org/lvfs/devices/