I have a 64.5 mustang and need to remove the speed needle from the speedometer. How do you remove the needle and how do you reattach in the same position?

 

Call one of the shops, like Mustang Depot who have the white face kits. They should be able to tell you for sure.
I have not done a '64-'65 speedo personally. All the ones I've done basically require using your thumb and forefinger to pinch under the needle this lifts the "press-fit" needle off the spindle. The key for me has always been not to allow my fingers to twist under the needle. This way I can put the needle back on exactly where it was at rest.
So if "at rest" of the spindle is 0 mph, then I make sure that while I'm pinching off the needle it stays right at 0mph. Installation is just pushing the needle straight down onto the spindle while insuring the needle is at the same mph as it was during dissassembly (0mph in our case).
Hope this helps.