Q: How can I reset the iCloud on my phone when old id was hacked?

Hello,

I need help changing the email account on the iCloud on my iPhone. The old Apple ID was a yahoo email address and unfortunately that address was recently hacked. I can no longer send/receive emails in the yahoo account so I've deactivated it and opened a new gmail account. I was able to delete the Yahoo account on the iCloud on my Mac because it had a simple +- button at the bottom. I want to change the email address on the iCloud on my phone but it keeps asking for the password of the deactivated yahoo account. I've tried verifying it through the "date of birth" question but it says my answer is invalid.

What do I do? Any help would be greatly appreciated.

Thank you!