It's simple. I, your friendly neighbourhood telemarketer, can show you how to do it in just seven easy steps!
Step 1: Hatch your Pokémon.
Step 2: Look at it's summary.
Step 3: Find it's ability.
Step 4: Search up your Pokémon on the highly esteemed Pokémon Database.
Step 5: Find that Pokémon's Hidden Ability.
Step 6: Compare it to the ability of your in-game Pokémon.
Step 7: If it's a match, you WIN!! It has its Hidden Ability! If not, re-breed and try again.