modifying .zip application (easy answer button)

[turdbogls]

Ok so i just downloaded this app the other day and really like it....
Download Easy Answer Button Free for your Android phone on AppBrain

the only thing i dont like about it is the look of the buttons. so i went into data/app and copied out the app to my computer. opened it up, looked at the drawable folder and found the images i wanted to replace. there were only 4.

so i found out their size (400x120) and made 4 new images that i wanted to use, put them on the SD card, used astro file manager to put them back into the app, and pushed the app to system/app, and changed permissions.

now i have done the widgetlocker mods using this method and had success. however, widgetlocker is a .apk, where as this app is a .zip file. so i figured, OK, lets try it in the data/app since that other way didn't work...still a no go.

just wondering how to modify these .zip apps, and get them to work.
any help is greatly appreciated.

if it is any help, attached are the files i am wanting to put in there.