2. Download SmartFlashTool_External.rar and extract it somewhere in root of C or anywhere of your computer.
3. Download Superuser.zip and copy it in root of your SD-cart!! DO NOT EXTRACT!!
4. Power-off LG Optimus Black
5. Press and Hold Volume + Button and insert your USB cable.
6. You'll Enter to Upgrade mode and see S/W upgrade please wait while upgrading
7. Run B_SmartFlashTool_Extern.exe
8. Choose ROM copy D/L bookmark
9. choose CP file: [PATCHED]V20N.bin
10. choose AP file: V20N.fls
11. click Start
Go to WC or make coffe or tea , or do whatewer you need , Do not stay near your computer
12. After successfully flashing
phone will reboot recovery
13. Wipe all data/factiry reset
14. flash Superuser.zip
15. Reboot system now
Thats All! Congrulations!
If you do all steps right, phone will boot and you have V20N GingerBread with Root and Touch Verison of Clockwork Mod.