Once you are rooted and unlocked you need to flack clockworkmod recovery. I have not tried the recovery flash in this tool. The way I did it....
1. Install Root Explorer
2. Install Rom Manager
3. Open Root Explorer> Toggle r/w permissions> Delete "/system/recovery-from-boot.p"
4. Open Rom Manager> Flash Clockworkmod Recovery
5. Power Off Phone
5. Boot into Fastboot
6. Select Recovery
7. Make a backup of stock
8. Download/place the ROM of your choice to the SDcard of the phone
9. Follow steps 5-7
10. Select install zip from sdcard
11. Find your ROM and flash.
12. Reboot your phone, and your done!
It just installs zips from the SD card and not directly from the pc
Sent from my Galaxy Nexus using XDA Premium App