Click on the puzzle to go to the puzzle page. Fill in the puzzle correctly and the final coordinates will appear with a message of success. Copy the coordinates down because you cannot cut and paste them. If you forget to do so and they disappear off the screen, just delete one letter of the puzzle and then fill it in again. The message will appear again. If you prefer to work on a paper copy, you can print out a PDF file using the link on the page, but you will have to then go to the web page and fill in the puzzle to get the final coordinates.
Note: I've had a report that this doesn't work with Internet Explorer 7, that is, it doesn't show the puzzle at all, just the PDF link. I've tested it with Firefox, Chrome, and IE11 without problems, so if you have trouble, try another browser.