So I'm a complete beginner at this, just letting you know. I hear linux's are a LOT better than windows, but I have windows and the tutorial I followed was linux, but said should pretty much be the same. Anyways I did something wrong. Lets simplify it real fast. I moved the calculator.apk to the root of SD. Put it to PC desktop. Renamed it .zip so I can extract it, res folder edited png, saved the pdf to png, overwright it, then i was told to highlight everything that was extracted and right click, press compress something which created a "resource.zip" which I renamed to calculator.apk, dragged it to droid and replaced the older one there, moved it back to original spot in /system/app, overwright again and now the calculator app is gone from app drawer. and in root explorer when trying to install it is saying a warning sign something about not installing. I can give a crap about getting the calculator back lol that's why I used it. But I need help understanding this more.