The user must navigate to the custom appendix they would like to preview. 

Located in the custom appendix box is the 'Preview Appendix' button. The 'Preview Appendix' button is outlined in red below.

Once this button is selected, the word document of the appendix will be downloaded (downloaded file will be in .docx format), ready to view. The user can also preview the appendix in the design wizard, exactly the same way how it is for reports and templates.