Galant 2000 Timing belt

I just wanted to know at what recommended mileage should the timing belt be changed. I know that everytime I go to the dealer and get my oil changed they say, your timing belts need to be changed. I only have 76,000 miles on her too.

I like to change the timing belt of my galant V6 mitsubishi, please inform me, all the points I have to take attention carefully. thanks. Gatot