There will be a waiting period while the bishops of the two Churches sui iuris (the one to which you are currently ascribed and the one to which you wish to be ascribed) prayerfully consider your petition. Provided that they both assent to the transfer, your parish priest will then be informed. Please note that receiving the assent of the two bishops does not complete the change of ascription. For the change of ascription to be complete, you will need to speak out loud, in front of the priest and two witnesses, a statement declaring your change of ascription. A written copy of the declaration should then be signed and sent to the Chancery. Your pastor will have the proper form for this declaration on hand. Remember it is by this positive act of your own will, manifested outwardly, that the change of ascription is effected.