Like others stated, add a lot of compost to the soil. As it breaks down, it'll loosen the clay. Over the next few years, the soil will get better and better as long as you continue to add compost.
Like others above, I live in Hawaii too and deal with all clay. I cleared an area roughly 60x60 and utilized approximately 60 wheel barrels of compost to amend the soil.
Here is a picture of a very large clump of Brazilians. The clump grew in compacted clay and it took a lot of water and sweat to dig out the matt. The area has since been amended with lots of compost and 2 Williams Hybrids are now planted in the spot.
