Go to the Age Groups page.

To change Ladies to Women for example edit the Ladies Age Group so that it is now Women by clicking the Edit button:

You will now have two Women age groups.

These remain separate although they have the same name.

To merge them to to the top and click Merge Duplicates under Manage Data (click drop down to reveal)

This will merge all scores, club records, and classifications to become a singular Women age group.

You may need to edit the merged age group so that it has the correct age limit and to ensure it is active.