Purchase
a copy on a CD-ROM or other digital form from a third party
distributor. The project maintains a listing of distributors;
however these distributors are not connected with, nor endorsed by
OpenOffice.org: https://distribution.openoffice.org/cdrom/sellers.html.
The
OpenOffice.org Porting Project has links to versions of the
software that have been, or are currently being “ported” to run
under various operating systems.
https://porting.openoffice.org/index.html.