Looks like I've got a coolant leak...I feared the worst initally but then I saw that the leak was from the air separation tank. It's a two piece bit of plastic and the leak is where they meet. I wouldn't mind doing it myself but I don't know what I could break in the process. Could a mazda dealer do this with no biggie?
Any idea the best way to go about fixing it?

 

The general consensus when this happens is to ditch the stock plastic unit and go with one of the aluminum ones, or to do the AST elimination routine.
My personal opinion is to replace with an aluminum AST, a lot of clever little Japanese engineers spent some time designing that system....too bad they chose PLASTIC for God's sake!