My dad has a health problem and was able to replace both of them . just unplug the harness from both (one at a time ) and there is a bolt holding a small clamp over the edge of the sensor. just remove and replace ,reinstall bolt and plug up. note one of our cars had a wire pulled out of the plug and had to be reinstalled then replace. just look for any damage to the harness the controll mod. is on the pass firewall and the harness runs close to the belts of car and could do damage . when this is done have the codes read by one of the chain car parts stores most will read it or let you use there reader and this will give you a clean start . hope this helps jeremy