The Royals can do that by non-tendering a player by this Friday's deadline at 10:59 p.m. CT, by trading a player or designating a player for assignment.
The two most likely candidates to have been non-tendered are already off the roster. Left-hander Tim Collins opted for free agency recently, and catcher Tony Cruz was designated for assignment. Cruz cleared waivers and is now a free agent.
The rest of the 40-man roster appears set, barring a trade, though the Royals could look to explore letting players like left-hander Scott Alexander or right-hander Brooks Pounders go in the hopes of re-signing either later.