You'll never get all of it out without stripping the stock. You can probably get some of it out by removing the stock from the action and standing it up on paper towels, tissues, old t-shirt, etc., in hot weather. The oil flowed into the grain, and some of it will flow out under the right conditions. You could also stand it in a pile of whiting. Some of it will come out by capillary action, but gravity is your friend and warm temps will reduce the viscosity of the trapped oil. You will still see the oil stains under the finish, but the wood will be helped by getting out as much as possible.
The good news is that if you strip and refinish the stock with oil, it will look even better than it already does.
