Oh yes, I understand now! Nothing is needed, only the ring. I just wore my ring to the boutique, took it off and gave it to my SA. I still have the certificate, the box etc. at home. BTW she just texted me today that I'll get my new ring on Thursday. I didn't expect it to be so quick, she's amazing!
Well if it's a new ring from a current style, they only need to open a draw no?