Stableford: how to put a zero score on a hole, using the scorecard


I'm new here, so if this question has been adressed earlier, sorry for that.

I don't know how to write a zero score for a hole in stableford, meaning I abandoned the hole because I can't get a moint anymore (say, 6 strokes on a par 3 e.g.).

Can anyone help on this?

And by the way, how do you switch from watch to scorecard? This is helpful to know how long you are searching for a ball, etc...

Thanks a lot for your precious answers.

Best regards,