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"