When to replace the third Ashur Tablet?

I play my third Ashur tablet, do I announce targets before or after I replace the card?



Ashur Tablets
Type: Master
Master.
Put this card in play. If you have three copies in play, remove all copies in play (even controlled by other Methuselahs) from the game to gain 3 pool and choose up to thirteen cards from your ash heap. Move one of those cards to your hand and shuffle the others into your library.

Replace, and then, choose targets. The 1/13 cards aren't part of the terms.
(LSJ 20091030]