One of my favorite Evernote features is that each note automatically includes the geo-location of where you were when the note was created. (Or, at least it does on iPhone, I'm not sure what happens on other devices.)
But I don't always create a note that's relevant to a location while I'm at that location. It took a little bit of research, and here's how to change the location of a note.
1. Go to the Evernote website and open the note that you want to edit. (You can't edit locations using the iOS app, at least as far as I can tell.)
2. In the Note pane, click Edit.
3. Click the note's location. It's not obvious that it's clickable, but it is.
4. In the location dialog that appears, enter new coordinates.
5. Click OK to save the new coordinates, and notice that the location has changed. It will show the place name after you click Done to save your edits.
That's it, you're finished.
But, wait, where do you get the correct coordinates to use in Step 4? That turned out to be the trickiest problem for me. Here's how to use Google Maps to obtain the latitude and longitude for any location.
1. Go to Google Maps and search for the location using its address or name.
2. Right-click the place marker on the Google map, then choose "What's here?".
3. Notice that the Maps search field has changed to the location's coordinates. Use those values when you edit the note's location in Evernote.