Overclocking Duron 850 (mobo MSI K7T Turbo Via 133)

I can raise the bus, but I want to lower the clock ratio to raise the bus higher. but I cant go below 8.5. I found a Bios flash that is supposed to let me go lower on the clock ratio. But I also saw that the Durons are locked. So do I need to pencil the Duron first or try the bios flash and change multiplier and bus in the bios?
Any ideas? Or am I completely lost?
Thanx for any help guys.

----------------J-----------------

Just unlock it first, and you'll be able to lower the multiplier in bios.

yup u have to unlock it but i wouldnt use a pencil id use a circut repair pen if i were u the results are much more satisfying