I did, just a few posts back last night. It's a very straight-forward install. Download it to the root of your sd card, rename it to "update.zip" without quotes, and reboot your phone holding the "u" key. Then select update from update.zip from sd or whatever the menu says. Provided your Replenish is on EF27 already, it will work fine. If you don't know, check "about phone" in your settings.
EDIT: Here is the link, once again.. http://www.firehak.com/ad1f8364d46c.SPH-M580_update_EF27_to_EK18.zip
EDIT: Here is the link, once again.. http://www.firehak.com/ad1f8364d46c.SPH-M580_update_EF27_to_EK18.zip