There are a few ways to change the stroke size in Illustrator. The first way is to use the Options bar on the left side of the screen. This bar includes a number of options, including stroke width, line width, and color. The second way is to use the Stroke tool. To use the Stroke tool, click on one of the lines in your drawing and then drag it to a new location. The third way is to use the Pathfinder tool. To use the Pathfinder tool, click on one of the lines in your drawing and then drag it to a new location.
