From the Property menu, find the property to which you want to add the brochure to
Click Details

Choose Select bespoke PDF brochure
Find the brochure on your machine, select the file and click Yes.

Go to Output and change the dropdown for Media to Web site.

Click Submit and this will then upload the custom brochure to the portals.
Note
If details on the property are amended then the brochure will need to be added again with the changes incorporated. The brochure is not automatically updated