1) Is your phone rooted?
2) If you answered "no" to 1), stop reading. This isn't possible otherwise. If you answered yes, then you can. These things are defined in a file called services.jar, and there are mods on xda that will do it for you. I found an out of date one, which won't help you, more than likely, but if you really want this, I can go find a more up to date one.
3) All this being said, with root, you can make your actual battery icon display the actual battery percentage just like the one you installed. The benefit to doing it this way is that your battery icon stays where it normally is, and you don't need an app for it. Of course, it's all personal preference, and if you like it on the left side, that's fine. Removing the battery icon can still be done.