I want to log in with a different Apple ID on my app store (mac)
I want to log in with a different Apple ID on my app store from my macbook, but I can't find where I can switch my account. It's now logged in with a different email -adress but I don't know how I can change it. Because now I can't download or update things, because I don't have the password of this Apple ID.
MacBook Air, iOS 7.1