if it's a filter you've downloaded you cant change the presets that exist. you can make new ones with the AA off or, you can alter the filter, which will put your altered filter in your 'my filters' category and you can then change the existing presets, but as long as you leave the downloaded filter in its original category you cant alter the existing presets. you can add new or alter the filter, but that's it.
it's actually something i've never understood about downloaded filters. it makes little to zero sense to have that limitation on the filters. since we can easily alter the filters why have this fixed preset thing?
If wishes were horses... there'd be a whole lot of horse crap to clean up!
Craig