Download and Install: The latest manasource Windows binary. The latest Wineskin winery. Now launch wineskin.
Step 1: Click create a new wrapper

Step 2: Name it something

Step 3 : Install Gecko engine if asked

Step 4 : View it in finder and launch wrapper (ManaSource.app)

Step 5 : Click Install software. Select the windows .exe you downloaded. Go through the setup (next, next, next...)

Step 6 : DO NOT select run Mana! Click Finish.

Step 7 : Point it to the Mana.exe. It should do it automatically.

Step 8 : Drag the wrapper (ManaSource.app) to your applications folder.

Step 9 : ???
Step 10 : Profit!

Have fun
