Things you need:
360 running Xell (ofcourse)
Gentoo Live V2 disc
an XBR image with your KV injected (ready to flash)
A USB drive with that xbr image and lflash.c
A USB mous & keyboard
01. Put Gentoo Live V2 disc in your 360 and bootup Xell/Gentoo
02. In gentoo, open up the terminal (Applications->Accessories->Terminal )
03. Type "sudo passwd" (withouth quotes), this will prompt you to enter a new password and verify it (the characteres of the password will not be displayed)
This will give you admin powers
04. Now we can mount the USB drive
Plug the USB in (rear USB port if you have used the front for mouse/keyboard
In the terminal type: "su" (without quotes) it will ask for your password, the one the just entered
Type "cd Desktop/" to change dir to Desktop
Type "mkdir flash" to create a folder on the desktop
Type "dmesg | grep -i "SCSI device"" (without the outer most quotes, the quotes around SCSI Device should be kept)
This will display a few lines similar to:
SCSI Device sda: ... (4GB)
The important part here is the part after Device (sda, could also be sdb, sdc etc)
Type "pwd", this will show you the path to the desktop
Finally type "mount -t vfat -o uid=gentoo,gid=users /dev/sda1 /home/gentoo/Desktop/flash"
Keep in mind to change the sda to the value you had (rear port should be sda) and the last part to what the "pwd" command showed + /flash
05. You should have a folder on the desktop named flash and inside you should see the xbr.bin (or whatever you called it) and lflash.c
06. In the terminal, type "cd flash" to change dir to the USB drive
07. type "gcc lflash.c", this will compile lflash and create an a.out file on the USB drive
08. type "chmod +x a.out", this will make it executable
09. type "./a.out backupnand.bin xbr.bin", this will create a file called backupnand.bin and flash xbr.bin to the NAND (change xbr.bin to the name of your file)
10. NAND should be flashed so turn the 360 off and boot up, and hope you get launched into a kernel