How to Modify or Hack android APK files using APKTOOLS [No Root] [Tutorial]

Want to change the car driver of Hill climb racing game to yours? Or want to change the Jetpack style in Jetpack Joyride? I guarantee that after fully reading this post, you will be able to customize any game or App, if you have a little brain, an idea and some patience. Just read below.

Tools Required

• APKTool to decompile and compile APK files
• SignApk to sign the recompiled APK files

I have uploaded the above files into a ZIP file. You can download it from HERE
Thanks to those guys who made APKTool and SignAPK. Actually I referred to Xda forum for the above tools. After downloading the files, follow the steps below.

Instructions

1. Extract the files and open command prompt in the extracted folder. There will be four folders.
   files , compiled, decompiled, and signed.
   Files  > Place your working APKs here
   Decompiled  > The files after Decompiling your APK will go here. You can edit the files after      decompiling.
   Compiled  > After editing and recompiling, the unsigned APK file goes here. You cant use it before signing.
   Signed  > Finished APK, after signing goes here. You can install the APK after signing.
2. Place the working APK into the Files folder and type the following command in the command prompt:
   (Here I'm taking hill climb racing as an example. You can take any game)
   

   apktool d files/hill.apk decompiled/hill

   
   
   
   
   
    The command is very simple. It says apktool to decompile the file which is situated in files/hill.apk and save the decompiled files to decompiled/hill folder (d is the command for decompile)
3. Now, just go through the files in the decompiled folder. It is very easy to mod. Here,I want to change the driver head of Hill Climb racing. So, in the assets folder., there is an driver-head.png file. It is obvious that this is the driver head image file. Now, edit the image using Photoshop (or anything similar) and change the head. Here, I have downloaded a photo from Google (dont know whose head is that! maybe an actress!!) replaced the head with this one and that's enough!. Be careful, when doing this, the photo should be in correct position. I mean, The Head should be above the neck and not should be in the AIR! I'm just doing this for this tutorial. If you want, you can change cars, tires etc. Also try editing the manifest file and other folders. In manifest file, you can edit the App name, version, etc.
   
   
   
   
   Now time to recompile.
   
4. For recompiling, open command prompt and type the following command
   
   
   

   apktool b decompiled/hill compiled/hill.apk

   
   
   
    I think there is no need of an explanation here. Command b is for Binding, I think.
5. Now the final step. To sign the APK file, you can use the SignApk (Provided in the Zip file). Type the following command
   
   

   java -jar signapk.jar certificate.pem key.pk8 compiled/hill.apk signed/hill.apk

   
   
   
6. Now transfer it to the Phone and Test it. Enjoyyy!

AAfter decompiling, you get the java files as .smali files. It is very difficult to edit it. If you try, you can do much more.

Here is the screenshot of what I have done

In games like Temple Run, they uses some applications like Unity3D to design such 3D games. I dont actually know how to edit those. If anybody know it, please leave a comment below and share your knowledge...

If you have any doubts or suggestions, comment below.