Spray the wood with the carpet cleaner K2R it will float the oil right out of the wood. You should be able to wipe off the white powder that results and sand. If its pretty soaked, you might need a couple applications. I had the whole front fall off a Super Sportster 40. The airplane lasted for years and the fuel finally got into the joints. A little K2R and some monokote and it was good as new.

Andy