if this TuT didnt help you check these out:
How to Install Battlefield: Hardline on your Jtag & RGH Xbox 360 Console:
http://www.xpgamesaves.com/topic/121658-how-to-install-battlefield-hardline-on-your-jtag-rgh-xbox-360-console/
[Tutorial] Battlefield Hardline Installation:...
[TuT] How To Make Battlefield Hardline Jtag & RGH run with Disc