the pan must be dropped to get the roll pin out, that holds the shaft in.
good luck. my suggestion is to take it to a tranny shop, it is a solid roll pin, it doesn't like to come out,there is only about a 1/16th that sticks out, it is very hard to get out. i usually end up drilling a hole on top of the case and driving it out the bottom, they make a tool so it lines up perfectly,and you don't miss the pin when drilling.