To remove your shared Facebook photos, go to your Account, found under the gear icon at the top right of any Classmates.com page, and select Privacy. Under Social Network Settings, click the red Delete Synced Facebook Photos button.
Following the steps above will delete any existing photos and prevent any future Facebook photos from being synced and shared.
If you'd like to keep your existing photos posted but opt out of sharing future Facebook photos, simply uncheck the box next Sync and share Facebook photos, then click Save my settings at the bottom of the page.
Keep in mind that syncing and sharing your photos is optional. You can still access your class photos page as long as you're connected via the Facebook Connect option.
If you just want to delete a certain photo or photos you've shared, simply hover over the photo and click the Delete option.