grind it out clean... when i did a few of mine i used a countersink drill bit. u can feather the edges out but use some pretty coarse sand paper, give it plenty to grip to. then i mixed up some gelcoat. then fill the hole and leave a little excess. once its nice and hard yer gonna sand it smooth (preferably with a block), then wetsand it, and the polish it. with that yellow you're gonna have to play with some of the tint and do some test splotches on something until you get the color right. gelcoat color changes as it cures. also polish the area nearby it so that it matches the clean polished surface color, not the dingy dull one before color matching.
crystaliner in costa mesa ca sells exactly what u need... Its a liquid fiberglass putty that has fiberglass beads in it and it comes colored ( for get coat) !! so just pick the yellow jar ( costs about 7 bucks ) you activate it with there resin hardner. Drys hard as a rock, sandable and water proof once its cut still!! It has the consistancy similar to bondo, so just fill it in, let it dry, sand it smooth and wala!! all fixed and its yellow! no need for any painting .. * to prep it all u would need to do is scratch the gouge with 150 grit ( only so the product has something to bite to) , and then clean it with acetone and its all ready.. I just used it on the bottom of my hull to fill in scrapes and gouges, bottom of my hull is white so i picked up the white jar of the stuff and it worked better then i could ask for!