The easiest way to improve your time at an OCR is to improve your running. There are tons of different ways you can do this, but people normally just choose one or two and neglect all of the others. We're identifying the most applicable things you might considering improving in order to get fast. These are in no particular order.
Your cadence is the number of steps you take per minute while running. A higher cadence is most often associated with running efficiency or running economy. Often times runners will have a low cadence which can lead to greater stress on the supporting joints, ligaments, and muscles in each leg as the leg supports the weight of your body for a longer period of time. Everyone is different, but typically a good running cadence is between 170-180 steps per minute.
2: Vertical Oscillation
As you run, your body not only moves forward but also moves up and down. That's normal. However, for many runners the amount of up and down movement it more than needed. A lot of energy is wasted with more-than-necessary vertical oscillation, and it can cause more impact on your joints and such. Developing a proper amount of vertical oscillation will improve your running and help you run faster.
3: Perform Strength Training
Just running will make you a pretty decent runner if you do it correctly. That being said, almost every single person who has ever run has weaknesses. They may be in your feet, ankles, calfs, glutes, quads, hips, or even your core. Incorporating strength training into you program can help increase your strength of movement and your structural stability while running. It can also help lower your risk for injury, allowing you to train consistently without harm. All of this adds up to improved performance and improved speed.
4: Evaluate and Improve Your Running Form
There are good running coaches that will conduct a form analysis for you. It's typically not expensive, and they can provide a lot of feedbag regarding what you can do to improve your form. This type of professional evaluation is invaluable for improving your running. I highly recommend that you at least work with a coach for a form analysis. It's isn't typically very expensive; especially considering how much improvement you can make thanks to their feedback.
5: Perform Speed Training
If you want to run faster, you will need to do some speed work. How much speed work you do is dependent on your training history and volume and the goals you have. That being said, classic training like Hill Sprints and 400/800 meter repeats will all help you improve speed.
6: Run More Miles
I've been training some miles the past few weeks with guy who ran track and cross country in high school and college. His best 1 mile time was 4:18. He was, and is, a fast man. He's talked a lot about his training and the training of his teammates and although they are all running distances competitively under the Half Marathon distance, they run a LOT of miles each week. Some of them climb as high as 100 miles per week. Obviously, you don't need to do that to improve. Even an increase of 15%-20% of your total weekly mileage over an appropriate amount of time can lead to significant improvements in your aerobic ability and overall endurance. This leads to greater capabilities for speed.
7: Foam Roll, Stretch, Warmup
Taking proper care of your muscles is essential for high levels of performance. The ability to move through full ranges of motion will absolutely help your speed. There is enough evidence regarding the benefits of a proper warmup that every fitness coach worth their salt program warmups into every workout.
If you work on any, or all, of the items on this list, you WILL get faster. It won't happen over night because nothing ever does with training, but it will happen.