Below we have a question, Q1, where 5% of respondents answered "0". For analysis, you may want to exclude zero values in summary statistics like "Mean". One way to exclude zero values is to recode them to [NA].
From the element's context menu select "Recode..." to bring up the recode dialog:
From here you can filter, select and drag responses to existing or new categories. For this example, we only want to code zeros to "[NA]".
Q1 now doesn't appear to have any "0"s, and "Mean" has increased. You can press the [NA] button to toggle whether missing values are included in the basis or not.