This wizard will be available with our new release of the site sometime next week.
In the mean time you can move old images to the deleted folder. Go to the Image Management screen and do a search for images. You have the option to search for all images older than a number of days that you specify. You can exclude images that are in active listings, saved listings, or in profiles. Then you can select these images 100 at a time and delete them. Once the wizard is in place you won't have the limitation of only being able to delete 100 at a time.