I have a 2001 chevy blazer and i want to replace the egr valve on it but i can not find where it is located and how you replace it and what it looks like can someone help?

Top front of the intake between the AC compressor and the alternator. Round thing like a tin can pointing right at you. Two bolts, 10mm socket and it will come right off. You can often clean the valve part and it will work ok, take a close look for a small chunk of carbon in the pintle area.