Okay so in the manual it says this:

 

Cirrus Textures

Cirrus textures can also be changed and distributed as freeware only to the community. Users cannot redistribute modified versions of the default artwork. There are 3 different cirrus textures with 3 different resolutions. The cirrus textures can be modified by painting the “Alpha” layer of the *.tga. You will need a program like Photoshop or Gimp to do this.

Cirrus Resolutions:

1. Low resolution 1024x1024
2. Medium resolution 2048x2048 3. High resolution 4096x4096

Installation:

Navigate to Resources/plugins/SilverLining/cirrusTextures/....you will see 3 folders labeled 1 thru 3. Inside each of those folders will be 3 more, labeled with the appropriate resolution for that particular cirrus texture. Install the appropriate texture into the folder and enjoy. Once you have the new textures installed it will be accessible in the UI. **make sure and backup the original files* 

 

 

But I'm not sure where to copy the file or folder into in order for them to show up in order for me to select it in the UI. Any ideas?

You need to replace the contents of one on the existing cirrus folders (1-3), after backing up its original contents. The UI for SkyMaxx Pro just has the three radio buttons for selecting a set of cirrus textures tied to the existing three folders; it won't add additional ones for new folders added in. (Unlike sky colors, where you can add as many as you like and the UI will pick them up in a list box.)