Mazda Repair: Mazda b2200 Computer Repair, mazda b2200, gm vechiles

Question
Hey I am having problems with my mazda and I know your a 626 expert but I think my question is pretty basic, I was wanting to get the computer I have in it rebuilt because I had it checked out at a local auto shop and they told me it needed a new computer first before they could diagnose the problem, they wanted to charge me 500 bucks, but I found a site online that would repair it for 150.  my problem is Im not that mechanical savvy and I wanted to know if it was difficult to pull out a computer and where it might be located?  I can do basic tune up rotor/cap spark plugs, change the oil, and am willing to learn.  I just wanna know the steps I need to take to take it out and was hoping you had some good advice.  

Thank you for your time,

-Isaac

Answer
computers are easy to remove and replace and normally are located in the center of the car under the dash close to the floor some are located in the engine compartment but that's tipical of GM vechiles

before you remove the computer:
purchase a static bracelet as a static discharge could damage the computer before sending it out for repair you may be better off seeing what a scrap yard would charge