I believe that you can. Let me look at my 5600HS (D) and one of the 'xi flashes to confirm that the shoe is the same; I think that they are.
I think they are too, so I went ahead and bought the 2000xi. I took the 5400HS apart last nigh and the hotshoe itself is wired to a connector which plugs into a socket inside the flash body. If the 2000xi has the same thing it should be an easy fix. The shoe and a tiny PCB is held on by four internal screws.
In life you only get one great dog, one great car, and one great woman. Pet the dog. Drive the car. Make love to the woman. Don't mix them up.