But thanks to Paul & his custom built program “SuperBoot“. it's become a lot easier to unlock, hack or root the Google Nexus One. According to him, superboot is a boot.img that when flashed, will root your device the first time you boot. the work is done automatically, no need to flash the system partition, no need to use ADB, no overwriting the ROM on your device, just flash the boot image.
Steps To Unlock nexus one bootloader in order to load any Custom Operating System
Step 1. Download and extract fastboot from here (Windows, Linux and Mac included)
Step 2. Run a command prompt / terminal at the directory you just extracted
Step 3. For Windows:
fastboot-windows oem unlock
For Mac OS X
./fastboot-mac oem unlock
./fastboot-linux oem unlock
Step 4. We're Done as the Nexus One Bootloader is Now Unlocked
After Unlocking The Nexus One Bootloader Successfully, Follow These Steps to Root The Nexus One in order to install your custom OS
Download SuperBoot From Here and extract
Step 1. – Switching to Bootloader mode – Turn off the google phone, then press and hold the trackball to enter the bootloader.
Step 2. – On Windows open ‘install-superboot-windows.bat',
Mac OS X – Open a terminal window to the directory containing the files, and type
chmod +x install-superboot-mac.sh
On Linux – Open a terminal window to the directory containing the files, and type ‘
chmod +x install-superboot-linux.sh
Step 3. You are done. Nexus One is now rooted to install any custom OS.