There are a few different ways that you can open your basement windows, depending on their individual design. If your windows have handles, you will simply need to turn the handle in order to open them. If your windows do not have handles, then you will need to lift them up from the bottom in order to open them. Some windows may also have a locking mechanism that you will need to disengage before opening the window. Once you have opened your basement windows, be sure to prop them open with something like a wooden dowel or plastic stick so that they remain open while you are working in the basement.