If you follow the official manual (the one from the manufacturer website) and respect the instructions, your warranty should be 'ok'. Because THEY are telling you 'how to', so they can't mislead you. They also may suggest you to do this way because it is easier, or the other way if you have some IT skills.
But just read the manual is not enought. I suggest you could read some articles and topics about overclocking to build a sense of what may be 'ok' or not.