For the collies we use a special Japanese ear tape and therefore have medical adhesive remover in the house. You can also use Goo-Gone to remove tape but make sure to do some alcohol, witch hazel or waterless shampoo afterwards. For the cardigans, I typically let it fall off on it's own, but use the removers if I need to take it off sooner.
This litter has ears bouncing all over the place. As noted, River has had one up for like 3 weeks now. They just need a little help to keep them up, so no bracing.
Rotate photo and you'll see how her's will look-heehee.