It is hard to tell precisely how to do it. Just need a little bit of practice. But when you're reading in English, one tend to read whole word, and not each letter. Try doing the same with Korean. But instead of reading whole words, you can start by just reading each syllable. Instead of reading like this: ㅇ-ㅏ-ㄴ-ㄴ-ㅕ-ㅇ-ㅎ-ㅏ-ㅅ-ㅔ-ㅇ-ㅛ, try like this: 안-녕-하-세-요. I hope it is understandable. A little hard to explain. Also, of course, after some exposure, certain words will become familiar, so you'll end up reading the word as a whole, and not each individual character.