Instructions (Method 1):
1) Place the zip file on your INTERNAL SD card and rename it "update.zip".
2) Boot into modded 3e recovery and choose "Reinstall Packages". You may have to do this twice the first time.
Instructions (Method 2):
1) Install ROM Manager from the Market and select "Flash ClockworkMod Recovery"
2) Select "Galaxy S i9000" (The partitions are identical. I checked.)
Disclaimer: This is not an official CWM recovery from Koush.