How to disconnect Google Plus from Youtube

[Bluelicious]

It seems you need Google Plus to log in to Youtube. The option to delete Google Plus makes you unable to log in to Youtube since you need Google. The problem is my Youtube username is showing up in my outlook mails when Gmail users send me an email. I don't want Google Plus nor did I ask for it they automatically made one along with my Youtube account. There seems to be no option to change that or disable public content from third party networks. How do I disconnect Google Plus from Youtube?

[Holac]

[Bluelicious]

Holac that option isn't available anymore. The settings have changed since 2013.