Either pop out the HD (which I've done when I upgraded my HD) and put it in a usb enclosure (much faster this way) so you can copy/paste the contents in a folder somewhere on your comp, or connect it to your comp using ak.sys. then sit and wait.
Now before you ask how to do all of this, there's a downloadable service manual that'll give you more insight on everything technical about the 4k right here under your nose.
MPC 4000
SSL Fusion
Roland JV1080
Ensoniq ASR10
Pioneer XDJ RX2
Korg Triton Rack
Kurzweil K2500RS
MiniMoog Voyager
Yamaha Montage 7
Yamaha Motif ES Rack
UA Apollo X8 Interface
Tascam DM4800/DA3000