1. I found an awesome collection of public domain WWII posters here: Northwestern University Library. Here is the image that I chose. Right click it and choose 'Save Picture As' (IE) or 'Save Image As' (FF) to save it to your hard drive, then open it with Photoshop.
Now get rid of the text by covering it up with the Clone Stamp Tool. I zoomed in 300% in this step. Select the tool, then select a round brush and set your brush size to 30px with a hardness of 50%. To use this tool, first Alt+click an area you want to clone. The cursor should change to the one shown:
Then click and drag around the text to cover it up. You may need to resample the background again a few times (with alt+click) to get a good cover up. Kind of hard to explain, but play around with it a little and you should get the hang of it.
2. Continue with the Clone Stamp Tool until the text is covered up. Add some new text, using Arial Black, 30pt, all caps, centered.
3. Using the Magnetic Lasso Tool (or use a quick mask if you prefer), draw a selection around the soldier's thumb, then hit Ctrl+C to copy and Ctrl+P to paste it on to a new layer. Move the thumb layer so it is right on top of the original thumb. If you do not understand the Magnetic Lasso Tool, check out my Kung Fu Silhouette tutorial for a more detailed explanation.
Now save this nice kitty image which came from Morguefile.
Draw a selection around your kitty with the Magnetic Lasso Tool. It does not have to be perfect. Mine was a 30 second job.
4. Ctrl+C your new cut out kitty layer to copy and go back to your poster and Ctrl+P to paste your cut out kitty on to the image.
Now you need to transform kitty to fit her in to the soldier's hand. With the kitty layer selected, hit Ctrl+T to 'Free Transform'. Now rotate her by grabbing right outside of any corner and rotating it approximately 90 degrees counter clockwise.
Now grab a corner and this time, hold shift while dragging the corner in to towards the center of the kitty to make her smaller, then move her up to the soldier's hand. Put her under the thumb layer that you cut out.
5. Use the Rectangular Marquee Tool to select the right part of the kitty that overlaps the poster border and hit the Delete key to remove it. That's it.
More Tutorials: 
