edit boot.img-ramdisk

[Guest add.thebad]

am trying to edit the init.rc but have problems extracting boot.img-ramdisk.gz

i have made a rom dump

then extracted boot.img

got boot.img-ramdisk.gz so extracted that

and now i have a file called boot.img-ramdisk nothing else

so how can i edit ramdisk?

thanks in advance. any help welcome