"procedure to decoding .apk files---step wise method-->
make a new folder and put .apk file (which you want to decode) now rename this .apk file with extension .zip (eg:rename from filename.apk to filename.apk.zip) and save it..now you get classes.dex files etc...at this stage you are able to see drawable but not xml and java file...so cont...
now extract this zip apk file in the same folder(in this eg or case NEW FOLDER). now dowmload dex2jar from this link http://code.google.com/p/dex2jar/ and extract it to the same folder (in this case NEW FOLDER).....now open command prompt and reach to that folder (in this case NEW FOLDER)....after reaching write "dex2jar classes.dex" and press enter.....now you get classes.dex.dex2jar file in the same folder......now download java decompiler from http://java.decompiler.free.fr/?q=jdgui and now double click on jd-gui and click on open file then open classes.dex.dex2jar file from that folder...now you get class file...save all these class file (click on file then click "save all sources" in jd-gui)..by src name....at this stage you get source...but xml files are still unreadable...so cont...
now open another new folder and put these files
put .apk file which you want to decode
download apktool using google and put in the same folder
download framework-res.apk file using google and put in the same folder
Open a command window
Navigate to the root directory of APKtool and type the following command: apktool if framework-res.apk
apktool d "fname".apk ("fname" denotes filename which you want to decode)
now you get a file folder in that folder and now you can easily read xml files also.
it's not any step just copy contents of both folder(in this case both new folder)to the single one
and now enjoy wid source code... "
Video Tutorial APKtool
Found in: stackoverflow.com