Apple Account recovery process for locked iPhone with unknown email password

Recently one of my friend changed the passcode to their iPhone while drunk and afterwards failing to unlock their iPhone multiple times they have locked their phone indefinitely. They asked me to reset their device as I was the one who set it up in the first place. Now while resetting the password I realized that the ID is "something@icloud.com".

Now while requesting for account recovery Apple told me that they will contact me when the process is complete on my email id which is @icloud.com. Now as I do not have the access to the inbox because I do not know the password to the email how would I know if Apple told me its okay to reset the password? Will they contact me on through SMS too as I have access to the mobile number linked to the Apple ID and email ID.

[Re-Titled by Moderator]

Original Title: Apple account recovery process