It's really not that tricky.
1. Most importantly, make sure the Zoom is plugged in and operating on the AC adapter rather than battery power or USB power from your computer. Check your Zoom for its firmware version. There are different versions of the update depending on what version you currently have. Download the one you need.
2. Extract (unzip) the files to your hard drive.
3. Copy the file called SYSTEM.BIN into the root directory of your SD card, that is to say, do not place it into any folder.
4. Turn the Zoom off.
5. Turn the Zoom on while
gently[/b] pressing down the bottom of the round menu button.
6. You will see the message Version Up? Below that are some icons and OK or cancel. If you do not see this message, you were probably pressing too hard on the menu button. Just turn the unit off and try again. GENTLY this time.
Use the jog dial on the left side to move the cursor to OK. Then press the jog dial to start the update.
7. Wait a couple of minutes until you see the message that the update is done. Turn the Zoom off, then back on again to initiate the new firmware.
8. You're done.