WARNING: The process shown in this video involves highly corrosive acids and should only be done outside or in a fume hood. Using safety gear such as gloves, goggles and a respirator is mandatory.
This is a step by step video that shows you exactly how to extract gold from old computer parts.
Specifically, how to recover the gold plating from connector edges also known as "fingers".
The point is to slowly etch away the copper and nickel to free the gold layer.
Copy and paste this link for more information on how to melt the gold and more!