There is currently something wrong with the thread, linking to the first page or any page that quotes the op sends you to the websites homepage, so for now, here's the page in the Harmonia thread where the developer announces the latest version:
[ROM]Harmonia 1.3 (Aphrodite + Picasticks) 17June11 - Page 50 - Android Forums
Install Terminal Emulator from the market. Once installed, open it and type su, if the $ sign prompt becomes a # sign on the next line, you are rooted fine.
Download the
Xionia Recovery and
Harmonia ROM to your phone, then use file manager to find them (they should be in /sdcard/download), copy or move them to the root of your sdcard.
In Terminal Emulator, type the following:
su
mount -o remount,rw -t yaffs2 /system /system
flash_image recovery /sdcard/NAME_OF_XIONIA_RECOVERY.img
reboot recovery
Once you are in the Xionia recovery, make a backup, DO NOT SKIP THIS STEP!
Next, wipe cache and dalvik cache
Next, choose install zip from sdcard, and select the Harmonia ROM's zip file
Next, choose reboot
You should now boot into your new ROM, it will take a while, you system has to rebuild alot of files, so be patient!
If you do have any problems once you flash your new ROM, turn off your phone, hold down the home_key+volume_down_key+power_button till the LG logo goes away, then it will boot into recovery. Choose restore backup, and you will be back to your stock rooted phone.