How to change the apple ID in Apps Store after i change it in my Settings?

I changed my apple id because my previous email address is no longer existing, now whenever i try to update my apps in App Store, it still shows my old apple id and asking for the password of it; apparently i have a wrong apple id because that is not my current one. I tried to log out and log-in just to see if this will work but nothing changes. Now, i have lots of apps to upgrade and i can't, i have an iphone 4 updated to iOS 7.1.2.

Scroll down to the bottom of the app store and sign out from there.

You can manage your Apple ID and set the primary email/password at…

https://appleid.apple.com/....apple.com