To do the following you'll need two types of tools. One being a reasonable image editor and the other being an .apk decompiler.
Firstly you need to know what you want to decompile, where this is a system resource or an average app. Go ahead and download an apk decompiler. There are many on xda but I use Quickmod as its the simplest.
Link to thread to download tool - http://forum.xda-developers.com/show....php?t=2536073
Once you've downloaded it, open the tool and installed the required framework and files for it to decompile and compile properly.
Once done, decompile the apk and head into the projects resource folder. It's labelled as "res".
You will then have to find the image you are looking to edit, using an image editor open the .png file and select the full image. Then just make the image larger with the small points at the end. And then just reposition the image into the center. Also you may need to refine the image after the resizing of it as pngs are used for transparency like images.
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