Pretty much plug and play. Although you do have to move the spedo cable from the hole in the support to the to the left, unless someone else done it a different way.
Is it possible to take them apart and swap your original odometer over to the new cluster? I'm thinking of getting a tach cluster,but I want to keep my milage the same.
^ not sure if you can swap the odometer portion or not. On my 90 Mazda, I disassembled the entire cluster and reset the milage to 0 just for grins. I sure you can reset to any number.