Originally Posted by himesh1910
I can't set the permission it says "some file system does not allow setting permission"
The problem is that your system is currently in RO (Read-Only) mode.
Even if you are root, can't change the system files.
ES File Explorer works because it has an option to mount the system in RW (Read-write) mode.
On my ES File Explorer its like this:
Android menu button--->Tools---->Root Explorer--->Mount R/W.
Set: /system (or all of the options) to: RW----->OK.
Now, explore your files using the ES File Explorer interface on your phone and you should be able to erase every file and apk you want even if they are system files.