For most car problems, you'll probably want the safety and reliability of a mechanic to handle any issues with the car. For example, nobody wants to perform a repair incorrectly and potentially damage a part of their engine or vehicle. This is why certified mechanics, who have advanced vehicle diagnostic tools, are typically the best solution for a complex job.
At the same time, there are a few things you can handle on your own, even if you're the most amateur of mechanics. A windshield wiper replacement is a good example of a job that everyone should be able to do on their own.
You do need to be careful when pulling the wiper blades up and away from the window, says Yahoo! Autos. If you struggle with the arm, it could snap back and potentially damage your windshield. Once you gently raise it, locate a tab at the base of the arm. This should release the old blade. You should then be able to slide your new blade into place. You'll know it's in securely when you hear a clicking noise.
Of course, you need to make sure your wiper fluid is good to go as well. This is something that a mechanic can spot during a tune-up and handle for you.