People usually scale them in the peppakura program.
Since you have a psd file I think you will have to choose a part like a wrist pad, and print it.
If it is too small increase the percentage to the file (Maybe in increments of 20%).
If it is too big decrease it a percentage.
Once that part fits right. Then change them all to that percentage.
Pretty much just eye balling it/ trial and error.
Thanks, Alpha Proto. I tried increasing the %s. it looks like it's increasing it in the preview, but I git print and it keeps just printing it on the 8.5 x 11" paper, instead of many pieces. I looked into tehe printing settings and see no way to make it the size I wanted.