Dana Point schoolteachers Charlotte Ruth Wyckoff, 52, and Elizabeth Leta Hamilton, 39, pleaded guilty to hiring a band of Alabama mercenaries to firebomb two cars belonging to former employees of their chain of private schools in Orange and San Bernardino counties. They entered the pleas in Los Angeles federal court a day before their scheduled trial with three other defendants. U.S. District Judge Alicemarie H. Stotler ordered the pair to undergo psychiatric examinations prior to sentencing Dec. 22. The women said they were trying to end a dispute with six former employees. Mercenary training instructor Frank J. Camper is among the three still scheduled to go to trial today.