Hi newcomer and welcome to the Tom's hardware forum.
1- What mobo do u have?
2- Usually every manufacturer have his own software to update the BIOS if u don't feel very comfortable with the BIOS update.
3- U can see here
a little guide for update the BIOS, it's a little old but the process is very similar today.
4- In this process u must be very carefully, because something can go wrong and recover the mobo could be very difficult. Some mobos (Gigabyte specially) have Dual-BIOS for this reason.