How does the installation disk work

[graftonskaggs]

Can I just change the install.sh to do anything I want or do I also need to make other changes. For instance if I just want to use the installation disk to run some bash commands so I insert the disk it runs some commands and then I pull out the sdcard and I have some files. Like maybe just use it to directly image the EMMC without having to do the install Also, where is the EMMC pin out.