I have an app uploaded to the play-store of Google , which I have been updating several times, without problems. While I was creating the update from the existing code with the Eclipse , every time I tried my application on my mobile, it erased the previous one and the new one was installed. And when I uploaded it to the play-store , I did the same with all the people who had the app installed. So far so good.
The problem is now:
I recently installed the Adroid Studio , to create an update to my app, but this time I want to rewrite all the code from scratch. And I've noticed that every time I try the application while I'm creating it, it is installed correctly, but it does not erase the installed one that I had already downloaded from the play-store . With which it does not replace the previous application but it leaves the two applications installed.
How can I make my re-created application with small modifications replace the previous one?