how to extract cdi in order to change 1st_read.bin?

Hi,
I've got the un-repacked version of zombie revenge and i've got the patch which is the 1st_read.bin that needs to be overwritten from my cdi image..

But i don't know how to extract all the files of the image in order to overwrite the 1st_read and how to repack it then..

Any clues?