The spreadsheet does not contain any macro.
kNN algorithm uses only simple MS Excel functions:
SMALL, which returns the kth smallest value of the array input
COUNTIF, which counts number of cells that pass some simple criteria
RANDBETWEEN, which generates random integer between two values
You can change any value of K (number of neighbors) or the data to see the effect of prediction.
Alternatively, you can just press F9 and it will automatically generate new random data.