you can cut a little piece of the middle of your sole and insole, and then glue the parts back together without the middle one, making the shoe a bit shorter. I did it once with some old shoe, just to see if it would work. The shoe ended up looking kinda weird, since the suede was now a bit loose, but it worked fine for a little while, but the glue i used wasn't anything great so it didn't hold for long. but if you don't care about how the shoe will look, it is possible with good enough glue.