I downloaded the files but I don't know how to make them bigger for putting on foam.
I've been using these files to make the patterns for the build I'm working on. It's a little involved, but it's not that hard.
First get all the measurements you need, according to the Prop Codex. You will need a height and width measurement for each piece.
Once you have the measurements, open the file for the piece you want to scale in Photoshop. There are a lot of layers, but right now you want to focus on the two that are un-grouped, "Height" and "Width."
Make sure the rulers in PS are visible, and select the height or width layer. Using the "Scale" Transform tool in PS, adjust the Black Width or Height Bar so that it has the same dimension as your measurement.
Once the Height and Width Layers match the dimensions you took, you have to adjust the scale of the rest of the layers so that the red triangles meet the white triangles on the respective bars. It's important to remember not to un-group the rest of the layers yet. Leave them locked together so that all of the pieces are scaled the same. Just use the Scale tool, but only focus on height or width one at a time.
Once everything matches up, you can un-group the layers, and move them (I just cut and paste) to the Platform File you should have downloaded, where they can be arranged for printing.
Hope this helps.
SC