Follow
this tutorial. It's fairly easy and it should do the trick. But remember to first save your original BIOS in case something goes wrong.
Few things with that tutorial.
1) Don't follow the instructions it gives you for creating a DOS boot drive. Just download Rufus, and have it do it all for you. I use the FreeDos option in Rufus, and I have a bootable flash drive in like 10 seconds. The other way is confusing, complicated, and unnecessary.
2) They have you download ATIFlash 4.07. ATIFlash 4.17 is the newest version, so I would recommend downloading that.
3) If you're already in Windows, you can use GPU-z to save a copy of your GPU's BIOS. Save it, and get right to work in VBE7. Saves you a reboot.