Um... I forgot to mention... You don't NEED to take appart the whole trans to change the shifter shaft...
#1: Drop the pan and filter
#2: remove all the old gasket from the transmission pan rail (transmission case)
#3: locate the shifter lever... notice the big nut. Loosen said nut
#4: Remove the pin that is holding the shaft in. It is inserted into the case from the lower side of the case on the pan rail. Use diagonal cutters to "gently" grasp and lever the pin out.
5#: Remove the big nut and and the "Z" link "should detach from the spool valve it's connected to.
#6: Remove both the shifter and TV shafts.
Assembly is in reverse order.
And, always a good thing.... PICTURES!!!
The nut:
The pin:
Another of the nut:
One of the valve body exposed:
Now, It's been some time since I last did this... but I'm sure that if you have the ability to replace the transmission, you have the ability to change these parts.
If you want to make it a little easier, you CAN remove the valve body... just make sure you make note of where each and every bolt comes from (they are different lengths)!
Good luck and feel free to msg me if you need more help.