Q: iCloud family email account. How to delete an email address, then add another

I have an email account in my iCloud family account which is inundated with junk mail, so much so that I would like to delete the account, setting up a new email address.

Could anyone let me know how to delete the current email account, leaving the other family email addresses unaffected, then set up a new email address in place of said delete email address.

Many thanks in anticipation,

Rich