what do i need to put disc brakes in 1964 deville with four wheel drums?

 

Money, and patience....and a donor car, probably.
You may be able to swap the spindles from a later model car onto the front fairly easily, but the rears are gonna be a little tougher. You might wind up replacing the complete rear differential.
You'll also need to replace the master cylinder, if you didn't already know that.
I don't have any specifics on this swap, so that's all I can say....