How can I rebuild hard drive?
Unplug all cables, pull the retaining screws, remove the old hard drive, match the jumper settings to a new drive and put the new drive back in place of the old one, reconnecting the cables.
Rebuilding a hard drive without a "clean room" and a LOT of expensive equipment is basically, impossible and definitely not worth the time and money required.
SOMETIMES it's possible to contract with local companies that will be able to retrieve some of the data from your drive, but it's expensive and the data had better be worth it.
EDIT: (not the original poster) One thing that you have to do is migrate the PCB from the dead hard drive into the new enclosure, because it won't work with PCBs from different hard drives. If the PCB from the dead drive breaks (including the read/write heads), then you have go on eBay and search for a PCB for the same make and model of the original HDD.