If you haven’t submitted secondaries for those schools, then you can just not finish them for now. If there’s an online way to withdraw, you can for peace of mind, but I assume most admissions offices are flooded with emails right now.
There’s no penalty for not completing an app or turning down the interview later. You can also attend an interview and withdraw afterwards if you still aren’t convinced by the school. I was definitely pleasantly caught off guard by some schools I interviewed at but didn’t initially have high on my list.