I have had a quick look at the code for this, the only simple way to allow images to be added and changed by someone non-technical would be to create a block that would place the image links in the JS and also add the corresponding HTML.

There are loads of jQuery Plugin Add-ons in the market place that use the same principle to allow the various options to be selected from a block. You could have a look at these for inspiration.

However if this is beyond your skill level it will take a bit of learning or you may be better getting someone to do it for you, a good developer should be able to create a basic block for this quite easily.