If the video software is capable of monitoring "live" via FireWire:
Connect the FireWire from the computer to the the camera.
Connect a video monitor to the the camera's S-connector or composite (yellow) connetor.
Connect amplified speakers to the camera's audio output jacks.
behind the terminal cover. Actually it doesn't say in or out... I was doing this from memory (which is dangerous :)) It switches from V2 (bnc) or the A/V1 terminal. Page 99... at least in the pdf manual.
I just connected my AH X1 to Premiere Pro and it is displaying SD output on both the viewfinder and external monitor. I don't think that you can pass HDV video back up the firewire to the camera.
One thing to watch out for - fire up Premiere before you connect the firewire to the camera. Otherwise the camera will stay defaulted to what it was doing before - If you were passing HDV, the camera won't switch to DV.
It is not possible to monitor HDV in real time through an HDV camcorder like you can monitor Standard Definition DV in real time through a DV camcorder. You'll need an interface like a Matrox MXO to monitor HDV in real time as you edit.