Torque converter solenoid 91 ford?

1991 f350 2wd, e4od. Want to replace tccs but not sure where exactly it is or how to get to it. Picked up repair manual, no help. Also, what is the sensor on tail housing by speedo cable

One solenoid block which has all solenoids on it, pull pan you'll see it has one 10mm nut and several 30mm torx bit bolts. Remove the harness connected to it on the outside and pull it off. On another note if this is a high mileage transmission and the t/c has never been replaced good bet the t/c is no good tripping the code if you have one. Several different solenoids over the years and you must use the 89-94 assembly for your truck

Hi just what do expect from a 26 years old truck not that it should still be driveable surely.