I did it by replacing the cable header with a 928K-ND firewire connector plug
from Digi-Key. This requires some careful soldering.

Craig M wrote:

Hey guys, I may be thick today and hope some of you can help me.

I have this case that has a standard 6-pin firewire jack on the front
panel of the case. There is a cable that connects the firewire jack to
a 6-pin header. I just bought a firewire card with 3 external ports
and one internal port. All 4 ports terminate in the standard 6-pin jack.

I may be missing something obvious, but how do I connect the front panel
to the internal port using the supplied cable?