I'm going off of memory here, so if I miss a step, I'm sure someone will chime in with a correction...
Connect the camera to the computer via firewire (USB won't work) and setup Final Cut Pro just as you would if you were capturing from tape via that camera. Switch the camera to camera mode. If all is correct, you should see output of the camera in the Log & Capture window. (You may have to consult the camera's manual to make sure it is sending the appropriate signal from the firewire port to the computer. I'm not familiar with the model of camera.)
Then, in the Log & Capture window, you would set it for non-controllable device. Then you would use the Capture Now button to record the signal coming in live.
I would not recommend this workflow, however, if this is an event that can't be recreated. If anything happens to the computer during capture, even a simple power fluctuation, the firewire cable gets kicked accidentally or someone heartily bumps the table the computer is on, you could lose everything that has happened between hitting Capture Now and the unintentional capture-ending event. Having a tape backup could ultimately save your bacon. (and there are about 6 more things I can think of off the top of my head that could go wrong with recording live to a hard drive via FCP... Some are recoverable, some are not.)
If this is a live event, I'd seriously consider looking into a AJA KiPro to use for capture. They can be rented for a reasonable amount, and the workflow is super-slick, especially is you need to have a fast turn-around.
If you're trying a stop-motion project or something, then it shouldn't be a problem.