Step 1
Start by removing your transmission pan and then your filter. On the inside, you wiring may not look like this as there are many different combinations or wiring for these transmissions. Remove the wiring, including the solenoid (middle picture) and the 4th gear pressure switch (right picture). Take note of the 'Z' shaped plastic guide and the bolt holding it in place.
Step 2
Once all of your old wiring is removed, start installing your new wiring kit but putting in the new solenoid where the old one was. Note that there is only one wire on the solenoid, this is because it is grounded to the transmission case.   
Step 3
Position the 'Z' shaped plastic guide as shown in the picture. Fasten it to the valve body using the same bolt you removed earlier.
Step 4
Install the new 4th gear pressure switch where you removed the old one from. You should put a spot of 242 Lock-Tite on the threads to prevent it from coming loose over time. Once it is installed, simply connect the two red terminals to the gold terminals on the switch.
Step 5
The last step is plugging the black connector into the transmission case connector. Note that on the black connector there is an extruded guide. This guide will index onto the case connector only one way. Be sure to line the up correctly otherwise the black connector will fall out, and your wiring will not work.