Changing the fuse on Christmas tree lights is a simple process that can be done in a few steps. First, locate the fuse box, which is usually located on the back of the tree. Then, use a screwdriver to open the box, and identify the fuse that needs to be replaced. Once the fuse has been identified, simply remove the old fuse and replace it with a new one. After the fuse has been replaced, close the box and test the lights to ensure they are working correctly. With these simple steps, you can quickly and easily change the fuse on Christmas tree lights.