PRIMARY MANAGER

I need to take an account off my list of accounts because the property was sold, however there is no UNCLICK button by this account, because it was the first account it set up and for some reason it won't let me take it off. The new company now wants access to this account, but I have about 6 others accounts linked to this and I AM NOT giving them my login and password.   How do I take this account off my account listJ????