Personally, I would airbrush it.
DO NOT paint Tamiya acrylics straight from the bottle. Decant a small amount and add about 30% by volume of Tamiya X-20A acrylic thinner. Stir well.
Before loading your brush with paint, moisten (moist, not wet) by dipping in clean thinner and removing the excess by touching the tip to a paper towel. Repeat this step every other time you load your brush.
Brush in short smooth strokes, preferably in one direction. DO NOT attempt to brush over areas which appear dry or have begun to dry, or you will pull it up in big ugly lumps. Allow to cure (preferably overnight) before re-coating.