How can I read the codes on a 1995 Buick Le Sabre?

I have a 1995 Buick Le Sabre that the check engine light is on. The local part stores say they can not read it because it is not 1996 or newer. How can I read the codes myself the local shop wants $100 for this and I can not afford that right now. The car cranks and runs fine but I need it to pass emissions and it won't if the check engine light is on.|||I don't think you can for pre 96 model cars. I have never found anyplace to do it|||With a paper clip and this info:|||auto zone read mine once and i have a 1988 oldsmobile. check with them if you have,nt already.