C4 Tranny Shifter Arm - How to take it out???

I got this new C4 tranny that I installed into my model A hot rod.
I run a column shifter in the cab and now that I have installed my rebuilt tranny it seems the arm off the side which connects to my shifter linkage is different.

I still have the old tranny and would like to swap arms but I am not sure how to tackle this task.

1st two pic show what works and needs to be installed onto my rebuilt tranny.
2nd two pic shows what I have on the rebuilt tranny that won't work with the column linkages that I have.

I am guessing it will involve an oil pan removal.
My tranny guy has shut up shop and just gone overseas on a long vacation and won't be back for more than 6 weeks.

 

You have to pull the pan and remove a nut I think it was ....its been awhile.

 

On the C6 you have to drop the pan, remove the valve body and take the nut off from the inside.

 

I allways remove the pan, loosen the nut with a hammer and long punch
spin the nut off by hand ,carefully swap shift shafts then again tighten the nut with a punch. leave the valve body alone.
I run a junkyard and have used this method hundreds of times without fail

 

Thanks for the information guys.
What I plan to do is follow the junkmans method by trying it out on the old tranny first and get the required shifter arm out.
This should allow me to get the hang of it without doing any damage and then move onto doing the swap in the rebuilt tranny.

 

I think you have to remove valve body.I couldn,t get mine off,but I used a locker shift so it didn,t matter.

 

Actually Junkman did not say which tranny model he was talking about.
I assumed it was for a C4 since that is what I am asking for help with.
My tranny is not the pan fill type.
The dip stick is in the tranny body and is an early type from what I know.
It came originally with a 289 out of a car of about 1969 era.

I figure if I attempt this with the disregarded tranny 1st up I can see how it works out on the bench and then decided from there.

 

The nut on the outside is for the kickdown shaft that is inside the shift selector shaft. The one on yours is already off. The nut on the inside is for the shift selector shaft. You remove the nut on the inside and it will stay on the kickdown shaft, slide the shift selector shaft out from the outside of the transmission, slide the other one in, line up the inside selector cam and replace the nut. I worked in a Ford dealership in the 70s and removed many of these to replace the shaft seals.