Just unplug the old bulb then plug in the new bulb and they work
It's important to have good working lights it will keep you from getting pulled over and ticketed for having a light out. Here's a trick backup near a store front and step on your brakes while looking. You can see if the bulbs are working. Don't forget to check your turn signal bulbs too.
What kind of vehicle do you drive? 2002 Jeep Liberty