To start the transmission must be drained of all fluid and removed from the car. Refer to the FSM for the proper procedure. You should also remove all external sensors and fittings (5th/reverse switch, "over top" switch, speedometer driven gear and housing). If you plan on resting the transmission vertically, like I did below, be sure to put some blocks under the bell housing as the input shaft does protrude slightly beyond the bell housing flange.
The first disassembly procedure removes the extension housing or "tailshaft" housing as it's frequently described. The first step is to remove the spring and ball assembly located on the back side of the extension housing. This is located underneath the hex bolt shown below. There should be RTV sealing the bolt so it may require force to break loose. Be careful removing the bolt as the spring and ball are compressed.
The next step is to remove the "cap and spring assembly," which provides the return spring force for 5th and reverse gears. These are located under the black cap secured with two bolts in the picture above. Be careful as the spring is compressed. Cover removed:
Cover with bolt, spring, and steel ball previously removed:
Cover, spring, and "cap":
Assembly note: the steel ball rides over the steps in the cap shown above so when reassembling ensure these features are facing the rear of the transmission. You have to hold the control rod end in the 5th/reverse direction while installing the steel ball and spring to make sure it engages properly with the cap.
Next, the "inspection cover" is removed, which is held in place with four bolts and sealed with RTV.
Removing the inspection cover exposes the control rod end, which is held in place with a roll pin, and the 1st/2nd gear return spring.
Use a hammer and a punch to drive out the roll pin.
Note: the control rod end needs to be angled toward the "right" side of the transmission (as if shifting into 1st or 2nd gear) to give the roll pin enough clearance to back out. If this is not done it will bind on the extension housing case.
Remove the eight bolts holding the entire transmission housing assembly together. They are located at the extension housing forward flange, which mates with the 5th/reverse housing rear flange. They will have RTV on them.
With the bolts removed give the extension housing some taps, alternating sides, with a rubber hammer to break the RTV seal. You will be able to slide the extension housing off the rest of the transmission. Hold the control rod so it doesn't fall to the floor. This is everything disassembled so far:
