Greetings,
You may not need to update your BIOS to have the 570 work on your machine.
I would try booting with the card first before committing to BIOS upgrade.
You'll either get an error, blank screen or it will boot.
If you determine you need U1G, the exe is a self extracting Zip and includes a utility for flashing. Use that.
I remember when Gigabyte released U1G for Z68 based boards. Some loved it, some didn't. You cannot go back, so see if the card works first with F7 before you upgrade.