There are a few ways to overlay pictures without Photoshop. One way is to use Microsoft PowerPoint. Open the two pictures that you would like to overlay and click on the "Layout" tab. Under the "Insert" section, click on the "Picture" button. From there, select the picture that you would like to insert. Once you have inserted the picture, click on it and drag it to the position that you would like it to be in. Another way to overlay pictures without Photoshop is to use the "Paint" program that is included with Microsoft Windows. Open the two pictures that you would like to overlay and click on the "File" tab. From there, select "Open" and select the picture that you would like to insert. Once you have inserted the picture, click on it and drag it to the position that you would like it to be in. A third way to overlay pictures without Photoshop is to use the "GIMP" program. Open the two pictures that you would like to overlay and click on the "File" tab. From there, select "Open" and select the picture that you would like to insert. Once you have inserted the picture, click on it and drag it to the position that you would like it to be in.