How ca I fix My External Hard Drive?

I Have a Maxtor (Seagate) 500GB external drive which was dropped. It has been making the inevitable clicking noise and my PC or Laptop doesn't register it when connected. In my paniced state I opened the bad boy up and now I'm wondering if anyone can help guide me through getting it working again. The disk inside isn't spinning when powered up and the reading arm doesn't move. ???? Help please. It has the whole of my daughters life in photos on it.