[Galaxy S II Themes and Apps] croperas:
I"m not An expert and my knowledge is limited to my own experience, but here goes:

1. Download APK Manager

Can be found here:

http://xdaforums.com/showthread.php?t=1227179

2. Extract The Original Phone.apk from your device, the Phone.apk file is located at /system/app/ folder.

You will also need the twframework-res.apk located at /system/framework/

There are numerous ways to do this, however i've only used two so here goes:

2.1 Download and install the Android SDK and use Android Debug Bridge (ADB) which comes with it.

Note: I think your phone must be rooted or you should use an adb shell exploit to gain a root user in order to access system files, such an exploit is available with the SuperOneClick, this can be found here:

http://xdaforums.com/showthread.php?t=803682

After that you can just use adb pull to copy the Phone.apk from your phone.

For example:

Adb Pull /system/app/Phone.apk c:/

2.2 A much easier way is to use an app called wireless file transfer pro, after starting the server you can easily access your phone via wireless, you can then type the path in the url to get to the system/app folder and download the Phone.apk file.

3. Unpack the Apk Manager and copy the original downloaded Phone.apk to place-apk-here-for-modding directory located inside the apk manager folder.

You will also need the twframework-res.apk file at your dispose, drop it anywhere, i copied it to the apk manager main folder.

4. Run apk manager and choose decompile apk with dependencies (option 10).

drag the twframework-res.apk from the apk manager folder to the console and press enter.

5. Go to the Phone.apk folder created inside the projects directory in the apk manager folder.

modify the bools.xml file (\projects\Phone.apk\res\values), set

<bool name="has_in_call_noise_suppression">false</bool>.

6. Go back to the apk manager console, choose select compressions level for apk's (option 19), enter 0.

7. Go back to the apk manager console, choose compile apk (option 11), select yes when it's asks if this was a system apk, when it says Aside from the signatures, would you like to copy over any additional files that you didn't modify

from the original apk in order to ensure least of errors choose yes, after that don't press any key in the console, instead go to the newly created folder called keep and delete the resources.arsc file. then press any key in the console to continue.

8. That's it, a file called unsignedPhone.apk will be created inside the place-apk-here-for-modding directory in the apk manager folder.

9. Now you need to copy and replace the new phone.apk with the original one.

you can do this using adb push or wireless file transfer pro used in the previous steps but those apps can't change the file permission so they are not good.

The only app that i've found and heard of that can change the system file permissions is root explorer, it's not free but you can use it to accomplish the final step.

10. Rename unsignedPhone.apk to Phone.apk and copy the file to your phones internal sdcard i.e /sdcard/, open root explorer, go to the /sdcard/ folder, find your phone.apk file press and hold the selection until a popup appears, choose copy, go back to the root directory /, go to the system/app folder, press mount as R/W (READ/WRITE), press the paste button at the bottom, scroll down to the phone.apk select it and hold the selection again until the popup appears, choose change permissions, adjust the file permission to the other files in that folder (READ is enabled to everyone, write is enabled only to user).

Restart your phone and That's it....

Done.