Where is shift solenoid for 91 s-10 blazere

The shift solenoid is in the valve body in the transmission, i recommend that if you have not worked on a 4L60 transmission before. Have a transmission tech do it for you, if money is the issue. You can drop the transmission oil pan and then drop the valve body and bring  it to a transmission shop and have them clean and replace the shift solenoid in the valve body just to make sure you replaced the right solenoid. There are more then one. Good luck and hope this helps.