Download Busybox from:

Select   and save it

Open a command line terminal: CMD.EXE or Bash Terminal, etc.

Change directory to your download path and then follow the commands below:

adb push busybox-armv6l /data/local/busybox

adb shell

su

cd /data/local

chmod 755 busybox

./busybox

mount -o remount,rw /dev/block/mtdblock4 /system

mkdir /system/xbin

/data/local/busybox cp /data/local/busybox /system/xbin

/data/local/busybox cp /data/local/busybox /system/bin

cd /system/xbin

busybox --install .

mount -o ro,remount /dev/block/mtdblock4 /system

sync

reboot

Note: You should change the device name [/dev/block/mtdblock4] for yourself by running command: mount | grep system