i think you take a bad way. All the instructions are displayed here :
http://www.rockbox.org/twiki/bin/vie...kbox_bootloade
To summurize, the things you must do are :
- patch the original iriver firmware with the rockbox firmware patcher to obtein a patched firmware (which permit to boot still on the original firmware or on rockbox)
- patch this modified firmware from the player running the iriver firmware (like you always upgrade your firmware player)
- copy the rockbox files (extracted from the zip files) provided in this page (
http://www.rockbox.org/daily.shtml ) at the root of your player.
- restart your player.