http://forums.androidcentral.com/verizon-galaxy-note-2/236929-how-edit-apps-use-multi-window.html
cd desktop\apk-multi-toolv1.0.10\apk-multi-tool\other
List the contents of the folder by typing dir
You should see the apk file you placed in this folder as well as the executables installed with you extracted the zip file.
In this example I will use the name mms.apk, you of course will use the name of the apk file you're modifying. If the file name has spaces you will need to put the file name in double quotes. Example: "mms 2.apk"
To decompile the apk type:
apktool d -s --no-src mms.apk (mms is the file name used in this example).
When the app has been decompiled it will look like the following:
I: Copying raw classes.dex file...
I: Loading resource table...
I: Loaded.
I: Decoding AndroidManifest.xml with resources...
I: Loading resource table from file: C:\Users\js\apktool\framework\1.apk
I: Loaded.
I: Decoding file-resources...
I: Decoding values */* XMLs...
I: Done.
I: Copying assets and libs...
You will now have a folder with the named mms (mms is the apk file used in this example) inside "desktop\apk-multi-toolv1.0.10\apk-multi-tool\other".
Now you can perform the same steps as above to modify the xml file.
After saving the xml file, go back to the command line and recompile the apk by typing the following:
apktool b mms (mms is just the example used here).
If the app compiles successfully you will see the following:
I: Copying classes.dex file...
I: Checking whether resources has changed...
I: Building resources...
I: Building apk file...
If the app does not recompile successfully this app cannot be used.
After successfully compiling the app, you now have to sign the apk file in order to install it onto your device.
To sign the apk file, type the following:
java -jar SignApk.jar -w testkey.x509.pem testkey.pk8 "mms.apk" signed.mms.apk (mms is only the file name used in this example).
You should now have a properly signed apk modified to work with multi-view.
You can now transfer the signed_.apk file to your device to be installed. The previous version of the app must be uninstalled first.