I don't think that's easy as your friend said, PCB for each and every hard disk is different, it's trial and error for some, but if you screw up, you lose your data in one swoop.
Best is to pay a little visit to specialize shop (can't remember which) and let them deal with data recovery.
If you want to recover it yourself, you have to find the PCB of which of the same model, same manufacturing batch and not just date, if your drive is old the chances is little high, but if it's new, then it's of luck, rarely new drive fail (can RMA after all).