So the kick down does not snap back? I did that too! About 4 times!
I made two long studs from some HomeDepot threaded rod and put them in the trans gently. Then when I had the valves in the right place (both shifter and kick down) I could raise it into position and the stud keep it perfectly parallel and guide it into place so it does not move left to right / front to back. Then you can hold it in place with one hand and work the levers with the others to be sure you got it right. Count the clicks for the manual lever to be sure you have that indexed properly - I put that in wrong and could not get back into park.