This is not my scripts, I found them on net, and I want to thank to author :)

Using:

Extracting

1. Place a working boot.img into this folder
2. Type:

$ ./extract_boot boot.img

3. Done. Now you can see a boot.img-kernel (zImage) and a ramdisk on extracted boot.

Repacking

1. After you done making changes on kernel/ramdisk, type:

$ ./make_boot boot.img

2. Done. Now you can see and flash your new boot named "boot-new.img"