how can i fix after over heating?

Make sure that the fan is now free to work and that there is no obstruction to the air flow. You may need to replace the fan as it's the component that is the most likely to have sustained some damage.

Make sure that there are NO foreing object nor dust in the air ducts. The air vents must be free of any obstruction.

Make sure that the heat sink itself is dust free.

When your computer started to overheat, it started throtteling itself down. When that proved insuficient, it shut itself down to prevent heat damage.

Final word: It probably did not suffer any damage and will work normaly.

Electro
September 2012