However, as cool and mysterious Clive Rivell is, for some reason GL didn't bring him back for RotJ, and we got Ian. HE is now the Palpatine of the Saga, and to keep the original in there just wouldn't be right. But if they were going to change stuff around, this is the way it should have been done:
VADER
What is thy bidding, my master?
EMPEROR
There is a great disturbance in the Force.
VADER
I have felt it.
EMPEROR
I have no doubt, the young rebel who destroyed the Death Star is the offspring of Anakin Skywalker.
VADER
How is that possible?
EMPEROR
Search your feelings, Lord Vader, you will know it to be true. The Force is strong with him. He could destroy us.
VADER
If he could be turned, he would become a powerful ally.
EMPEROR
Yes, he would be a great asset. Can it be done?
VADER
He will join us or die, master.
Just a simple re-edit of the existing scene, taking out repetitive and unecessary dialogue. I'd also alter the music to the Emperor's theme.