Darth Venal said:

Well anyone willing to give that a go deserves points for trying. Personally, feelings of the change being unnecessary aside, I think the technical side of it is also going to be very difficult. Apart from the tricky job of rotoscoping Alec Guinness out of Dagobah, you've then got the added issues of Dagobah still being visible through him instead of Ben's house. And while you can animate the outline of Ben with Force energy and use the glow to hide the rotoscoping, it can't be done with Luke. It's a hell of a lot of work.

Good luck with it.

One can always take Alec Guinness scenes from ANH and transparentize him, if that's possible. Whenever he speaks, never show his face (be it we see Luke's face and the side of Kenobi's, and then the camera angle changes so when Luke speaks we see Kenobi sitting/standing while listening to Luke).