The office-bearers are elected by the committee so you could try to get a majority on the committee at the next AGM.
Alternatively, you could demand an Extraordinary General Meeting and pass a motion to remove them from the committee entirely but that would require a 75 percent vote of owners voting in person or by proxy.
Or you could canvass the existing then present a motion for the next EC meeting declaring the office open and inviting the election of new office-bearers (this requires, of course, the support of the other EC members who will also have to stand for the vacancies.)