Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You have to learn the なお part. Think of it this way. You need to fix something! It's urgent! You have to fix it now! (なお). This will also work with the similar word, 直る, which you'll learn soon if you haven't already.
My PC broke. Can you fix it?
You'd better think it through again.
You don’t need to fix something if it’s not broken.