As Dschijn stated its do-able, but if you don't have a lot of faith in your soldering abilities, this is the solution that many have used on this forum...
Here's a brand new unused one at a good price.
http://www.ebay.com/itm/APPLE-Front...440?pt=LH_DefaultDomain_2&hash=item19dbb197d0
You can also purchase AlohaCab's cable (
http://www.g5modders.com/alohacab/) plug 'n play solution for full functionality of your front panel. Total cost of both parts will be about 80 dollars shipped. Aloha's cable grounds the G5 front panel through the Firewire header as the original G5 did, so you'll have to do one of three things to ground the front panel properly
1. Connect Aloha's cable to an existing 1394 Header on your board if it has one.
2. Re-Route the ground pin on the Aloha's firewire header to a ground pin on your board.
(He may be able to make one this way for you if you ask prior to ordering)
3. Buy a PCI-E Firewire Card like this one that has an internal 1394 header.
SYBA Low Profile PCI-Express 1394B/A Firewire Card Model SD-PEX30009
Ersterhernd