You will have to sign a message from the former wallet to prove you own that wallet before the change can be done. That is the procedure here from my observation.
For what it all is, does not need that, he is not hacked, or request a loan, must do everything in a signed message, do not need it.
@giammangiato, you only need to notify @Hhampuz via PM, BTC address changes, confirmed. Done.PM responds more quickly to your complaints, rather than posts here, instead of @Hhampuz seeing your post.