2000 Chevrolet S-10 Where is the tcc solenoid?

The truck is my boyfriend's and its thrown codes regarding the torque converter clutch solenoid. I'm just trying to find out if it's actually inside the transmission (like a non-mechanic friend has said) or if my boyfriend is right and its outside of it? My boyfriend is very tightfisted and is trying to get average Joe to fix it in his home garage but I don't want him to do that and end up with a truck in worse shape than its in as it is currently still running. Especially if this part would involve cracking open the transmission.