Steps to clean a cat's ears:
1. Check the cat's ear discharge to see if it is infected. If it is earwax, you can clean it yourself. If it is ear mites, you need to see a veterinarian.
2. First, use pet-specific ear cleaning solution to clean the cat's outer ear wall, then wipe it clean. 
3. Put 3 to 5 drops of ear cleaning solution into the cat's ear to dissolve the earwax in the cat's ear canal.
4. Gently wipe the cat's ear canal with a cotton swab. If it cannot be completely cleaned in one go, you can repeatedly apply the solution and wipe again.
5. After cleaning, put ear drops into the cat's ear canal and massage the cat's ears to help absorb the ear drops.