How do I switch back from Alias to a separate account

I have 2 email addresses go into 1 account by using an Alias.

Example: John@johnsmith.com and Info@johnsmith.com. If I log into john@johnsmith.com it will show all emails to John and Info.

I now want to separate the 2 email accounts:

and

When I try to add info@johnsmith.com it says it already exist but I'm guessing I need to delete the alias first. Is that correct?