1. First, open a new image. Make sure that it's the size of both of your images put together.
2. Copy one the of images and paste it on the new image.
3. Make a new raster layer. Take the second image and paste it on the new layer. Have it overlap the first image. Here's what mine looks like:
4. Now take your selection tool and match your settings to mine:
5. Select the edge of the top image and press the delete key a couple times until the two images are blended together how you want them to be.
6. And there you have it! Here's how mine turned out:
