Engine Mechanical problem
2002 Mitsubishi Lancer 4 cyl Front Wheel Drive Automatic 108000 miles

I was recently told by a mechanic that I am going to need to replace my timeing belt on my 2002 lancer oz rally. He said it is time that it needs to be replaced every 45-60,000 miles. I was wondering how to change it myself, I have basic mechanical skills. My mechanic told me the job would cost 350.