Insure you have battery charged half way or more before updating!
Download to your PC.. then Rename it update (it should look like this when done: update.zip).
Copy it to the root directory of your SD card (using usb cable), turn phone off, then power back on holding Vol-Down and End/Power, wait for option screen.. might take a moment or so.
Choose "recovery" from options (use Vol UP/DOWN keys, Power/End to select), then "Apply sdcard:update.zip", it will unpack the update etc.. then another option screen will appear..
Choose "Reboot system now"..
When it reboots you will see a green circle made from two arrows (looks like the round sync arrows) with an straight arrow in middle.. this will happen a couple times.
Then it will start to boot up like it usually does.. just slower..
It will hang a bit on the Verizon LOGO... don't panic... just wait... and now you are updated!