Start off by adjusting the height of your bridge. The bridge is the plastic piece between your strings and tuning pegs. The bridge mostly depicts the high and low action of your guitar. Always use a pencil to mark your bridge so you can shave it off in case it’s too high.
Now it is time for you to get to work. Since you have already put a mark on the bridge, use a needle to shave the bridge off. An acoustic guitar mostly requires you to lower its action. Therefore, try to cut the bridge down a little so that the strings can come closer to the fret-board. Sandpaper will get the job done perfectly for you.
Now it is time for you to put the bridge back into its original place. Once you have done so, start re-stringing the guitar. Make sure that all your strings are equally set apart as it can always be a problem for you later.
Do not judge the height of the action before you have played on it. Start playing your instrument and you can decide for yourself whether the action is good enough for you or not. It is mostly comfortable if it is not too high. However, some people prefer a mediocre action and if you are one of them, then you should be careful while trying to shave off the bridge with a needle, or even sandpaper.
There are always hitches during experimentation. In case you are not satisfied with your action, you can always repeat the same course over and over again. However, do not try to shave the bridge time and time again. You might have to buy a new one soon, once you have broken it or reshaped it into something that is not desirable for you.