How do I replace all belts on a Volvo 740.?

To replace all belts on a Volvo 740, start by disconnecting the negative battery cable for safety. Remove the accessory drive belt by loosening the tensioner pulley and sliding the belt off. Next, for the timing belt, remove the timing cover and carefully align the timing marks before loosening the tensioner and replacing the belt. Finally, ensure all belts are properly tensioned and reassemble any components removed during the process.