How To Mod APK on Android

Steps On How To Prepare Our Workspace:
1. Gawa muna kayo ng folder and let's named it as "APK MOD".
2. Download nyo yung tatlong file ("one_click_signer.rar", "apktool1.4.1.rar", and "apktool.jar.rar") to our created folder which is APK MOD folder.
3. Extract one_click_signer.rar to APK MOD folder.
4. Extract apktool1.4.1.rar to APK MOD folder.
5. Rename apktool.jar.rar to apktool.jar.
6. Copy and paste apktool.jar to apktool1.4.1 folder.

Steps On How To Edit/Modify An APK:
1. Paste the apk(e.g FILENAME.apk) you want to edit to apktool1.4.1 folder.
2. Double click "Command Prompt.bat" to run apktool in parent directory(apktool1.4.1 folder).
3. Type "apktool.bat d FILENAME.apk" without quotes and hit ENTER to dissassemble the apk you wanted to edit. A new folder should appear named FILENAME.
4. Now you could take advantage of whatever you wanted to modify in disassembled apk(FILENAME folder) as long as you know what you are doing.
5. After all modifications to the disassembled apk(FILENAME folder), type "apktool.bat b FILENAME FILENAME_MOD.apk" to assembled it again. Note: FILENAME_MOD.apk is the newly modified apk.

BUT that is not yet complete because, if you install it, it will give you an error regarding license. Please follow next steps to signed it.

Steps On How To Signed An APK:
1. Copy and paste FILENAME_MOD.apk to "one_click_signer" folder.
2. Double click "one_click_signer.cmd" to run the signer.
3. Type "FILENAME_MOD.apk" without quotes and hit ENTER. A new apk should appear name signed-FILENAME_MOD.apk.

Before installing the modified apk, please uninstall first the original apk. Note: Please make sure that a backup copy of original apk is available before uninstalling. Enjoy.


source :  http://www.symbianize.com/showthread.php?t=549156