Add them using Windows Control Panel / Fonts. There is no special way to add fonts for OpenOffice. If they are on the system, OpenOffice should see them. Some fonts can show up problems on Windows and/or OpenOffice.
Apache OpenOffice 4.1.3 on Xubuntu 16.04 (mostly 64 bit version) and infrequently on Win2K/XP
14 October 2016 was Pooh's 90th birthday