How to decompile android kernel within android itself?
No. You can't decompile within android. Not only hardware isn't probably strong enough for compilation/decompilation in most cases, but how do you plan to edit such a huge code in android itself? You will infact need special editors like notepad++ or gedit even in PC to organize the code and be able to understand it to edit. Plus its not "kernel.bin", its " boot.img".

So well, PC is only way for now ;)