How can I fix my camera's "lens error"?

Nate, couple of issues that you have going against you. Even so Rice is a great first aid, it will not prevent corrosion damage. I would suggest that you disassemble your camera and clean every part thouroughly with isopropyl alcohol and a soft brush, even the lens. Once properly cleaned, check for any further corrosion and missing components. Do not forget the inside of the connectors. Reassemble your camera and re-evaluate. If it still should not work, it is best to replace the lens. Yes, it can be disassembled, but it is very difficult to find parts for the lens mechanism etc. Hope this helps, good luck.