Well, really, the first thing you should do I read a bit about PHP (web tutorials and introductions to PHP programming) to get a better understanding of how things are "flowing" in the plugin. Then you'll be able to know where it is sensible to move parts of the code from one place to the other. Often the code needs to be executed in a predefined order to do its "magic"
I know this sounds "dry" as an answer, but this will help you in the long run if you intend to further do customization to indexhibit's templates and plugins by yourself.
I never used the slideshow plugin itself, so i can't really give you a precise answer, but an educated guess would be that the line close to ** DON'T FORGET THE TEXT ** // would be responsible for the text content output of the plugin. By moving this after the output of the images, you should get the result expected.
Once again, you can do this by trial an error or you can read a bit about PHP code structures and variables and will become somewhat able to "read" what's happening in the code. This won't make you a programmer, but it will let you hack the code around with confidence and that is mostly what's needed to do customizations to indexhibit.