1. Do a partial water change to reduce levels.
2. use amquel plus or Prime by Seachem
3. Do another partial water change in 1 day.
It really is that simple to reduce or remove ammonia. It does take a little time to reduce ammonia so be patient. After you reduce it, dig into why you are having a problem. You either have to many fish, your tank is cycling. or your over feeding. So find out why you are having a problem and fix it. Also Do not remove or replace your filter media.