Make a copy of the topic.

Select the Dotted Menu (...) for the copy in the Content Manager.

Select Edit and choose Open Structure.

Change the Subtype to Informal topic in the Metadata Section. ⌄

Select Update.

Close the Structure View with the X in the top right corner.

Select the copy in the Content Manager to open it in the Editor.

Remove its title element.

Your topics will contain a title, so there is no need to have an additional title in the informal topic.

Select Save.

Select the origin topic Content Manager .

Insert the created informal topic.

Remove the part that became the informal topic.

Select Save.