The actors will appear on the Jan. 30 episode of the sitcom.
"In the episode, multimillionaire Marty Pepper [played by Reiner] proposes to Evelyn [played by Holland Taylor]," a synopsis released Wednesday said. "In advance of their upcoming nuptials, Walden [played by Ashton Kutcher] and Alan [played by Jon Cryer] throw Marty a bachelor party. Marshall, Conway and Lawrence play Marty's friends who help him celebrate his last days of bachelorhood."
2014: The Year in Music [PHOTOS]