To use the example code; download the file and unzip/extract. Connect a micro:bit to a spare USB port on your computer. The micro:bit should now show up as a removable disk onto which you can drag and drop the .HEX file that you extracted from the zip file. Once the light on the rear of the micro:bit stops flashing, the transfer is complete and the program can now be run. Try experimenting with the A and B buttons on the micro:bit. You can also drag and drop the file into the MakeCode editor, where you can look at or edit the code.