The most common way is by sea, usually from South America via cruise ship or yacht charter—Ushuaia is a popular departure point.
White Desert does not offer sea voyages to Antarctica. The oceans can be rough, with passengers via the Drake’s Passage especially reporting seas that cause seasickness even in normally strong-stomached travellers.
While some of these charters offer short expeditions onto the ice, accommodation is on the boat, so you’ll wake to views of Antarctica’s ocean and sometimes coastline rather than its landscapes.
Avoid all this by flying in and staying on the ice!