Caught the ferry from the CBD, which then went through Devonport and then landed at Matiatia. From there we caught a shuttle up to the start of the Sculpture walk itself, but I'm sure you could walk it.
The walk is free and the brochures that explain the artworks are $5. There is a little station at the start that you can purchase brochures and water from, and half way around there's a delightful coffee stall, which also had hot chocolate but not trim milk.
The walk itself is actually part of the track to Church Bay, winding around the edge of the peninsula that is to the right as you enter Matiatia on the ferry. Lovely views and a well constructed track in most parts (although I understand there are some local politics around land-owners encroaching on public walkways through out the island).
The sculptures were modern, and mostly very clever. I particularly liked Clip Clop, which is a bridge with lose planks that create a xylophone effect. The blurb in the brochure talks about the story of Billy Goat Gruff and there is an obviously political element to the piece, in terms of local land ownership and use issues.
There's also a great fun work with orange and pink hats and scarves which you can use and return to a wooden box later on the walk.
Here are some of the pics of the sculptures, which are arrayed along the cliff edges, taken by my colleague:
All up I think it took us maybe an hour, but I don't have a watch. I didn't even have to wear decent walking shoes - just slides - and at time I went barefoot as it was nice grass.