It's easy! All you need to do is take one end of the light string and plug it into a power outlet. Then, start at the bottom of the tree and work your way up, weaving the string in and out of the branches. Make sure to spread the lights out evenly so that the whole tree is covered. Once you reach the top, use the remaining lights to decorate the tree topper. Don't forget to check that all the lights are working properly and adjust any that may not be. Now, you have a beautiful, festive Christmas tree!