To edit the condition, select your conditinal text and click
the Conditional Text button 
on the D2HML Styles toolbar. You can make any changes in
the Condition dialog box.
You can also edit the comment directly, if necessary. Right-click the conditional text and select Edit Comment. Edit the platform, target or attribute properties.
Note: If editing classic Doc-To-Help conditional text, remove the conditional text comment and specify a new condition as described in Adding Word Conditional Text Comments.