Restoring a gravel driveway is much easier using a box blade w/ rippers or a grading scraper, but you can use just a FEL to knock down the crown, just like you would with a small skid steer.
Drive forward using the bucket to cut down the crown until the tractor starts to bog down a bit, then back up and spread the bucket load on each "track" on the edges of the driveway, overlapping the gravel in the center to create a slight crown. Then back-drag each side of the gravel to smooth it out. If the drive has too much crown for your liking, you can back-drag the center to get it the way that you want it. Once the grading is done, recompact the driveway by wheel rolling the driveway with the tractor.
Remember that you need to get below poor drainage areas, potholes and washboard, or they will return fairly quickly. That's where the rippers on a box blade or grading scraper shine.