If you find yourself constantly joining lines in Illustrator, there are a few tricks you can use to get around it. Here are three methods for unjoining lines:

  1. Use the Direct Selection Tool (A) to select the line you want to unjoin and press the Delete (Backspace) key.
  2. Select the line you want to unjoin and choose Object > Ungroup from the menu bar.
  3. Use the Free Transform Tool (T) to resize and move the selected line until it no longer intersects with the other lines. ..