Next Previous buttons on Garnish Theme image gallery

Hi there,

I am using Garnish theme which includes a portfolio page. The standard portfolio has next and previous buttons, but these move between portfolio items, whereas I would like them to change between pictures.

If you click on this link and then click on the first box on the second row (Too Many T’s) you will see what I mean: http://vinylsoundfiles.co.uk/tink/portfolio/too-many-ts/

The best I can do so far is add navigation buttons below the picture for each image, but I would simply like the current next and previous buttons to scroll through the pictures instead of the other portfolio items.