Qualifying points for the other six spots will be earned via one ranking list weighted towards performances in the majors and biggest PGA Tour and European Tour events.
Since Europe beat the USA 16.5 to 11.5 in Rome last year, Jon Rahm and Tyrrell Hatton have joined the wave of big names lured to LIV by huge signing bonuses and prize money.
But the Saudi-backed Tour remains off the qualifying criteria and players must remain members of the European Tour to be eligible for the Ryder Cup.
That means the likes of Rahm and Hatton will have to play four regular European Tour events this season to maintain membership.
"A lot of work has gone on behind the scenes to get to this point and everything is now focused on doing all we can to retain the trophy in New York next September," said Donald, who led his side to victory just under 12 months ago.
The new qualifying format replaces a two-tier structure based on world rankings and European Tour points.
"This is a major milestone moment in our journey to the 2025 Ryder Cup," said Guy Kinnings, chief executive of the European Tour Group.
"This is without question a much cleaner and simpler qualification system than the ones utilised in previous years and we thank Luke and his vice-captains Edoardo Molinari and Thomas Bjorn for their vital input over the past few months."
Europe are aiming to retain the trophy on US soil for the first time since 2012 at Bethpage Black Course on Long Island, New York from September 25-28 next year.
