If I wanted to add some of my own icons to an existing Icon Theme, how would I go about doing that?

I'm assuming I'd have to use APK Manager to open the package and add the image files but where do I find the exact name of the app/icon I want to add? For example, the package I'm using doesn't include an Astro File Manager icon. I have an icon for it but just placing the icon in the image folder and naming it Astro won't work. I have to have it's proper name. The Netflix icon is named com_anddev_netflix_netflix.png. Where do I find the exact name needed for the app/icon?

After I finish adding all the properly named icons I planned on using APK Manager to recompile my file. I should then be able to just install it like any other apk file.

Is that the proper way to do what I want to do? Once I get the file names corrected?