step by step how to replace heater core on 1999 chevy s10 pickup on 1999 Chevrolet S10

I have no heat at all. used to work until I had a coolent flush a few months back

Asked by for the 1999 Chevrolet S10
Try flushing the heater core itself first! It is major repair for a seasoned mechanic to replace that core!! Check youtube for a video on flushing it out.
1 more answer
Before I got into the heater core I'd check the thermostat first then make sure the heater control is working