Install/Uninstall .apk to System Directory on Android

Here is a simple way of installing and uninstalling an .apk to system directory on Android.

1. Open adb shell
2. su
3. mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
4. cat /sdcard/[YourAppName].apk > /system/app/[YourAppName].apk
5. mount -o remount,ro -t yaffs2 /dev/block/mtdblock3 /system
6. reboot

To uninstall issue following commands:

1. mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
2. rm /system/app/[YourAppName].apk