Hal Riney & Partners, San Francisco, has redesigned creative leadership on General Motors Corp.'s Saturn account. Dave O'Hare and Steve Stone, formerly at Goodby, Silverstein & Partners, succeed Steve Baer and James Dalthrop as senior VP-creative directors on the account. Messrs. Baer and Dalthrop have left Riney. On Monday, the agency will present a dozen new spots produced by the combined team that retain the original "A different kind of company, a different kind of car" theme. Spots will run in August, when the new cars are in showrooms.