Download Aero Ultimate.7z.

Open/Extract the .7z archive. You can use 7-Zip to do this.

Create a Skins folder in the root of your flashcart’s SD card.

Inside the 7z archive, you will find a folder called Aero Ultimate.

From this folder, copy Aero Ultimate.skn to the Skins folder on your SD.

Place the SD card back into your cart, and launch Moonshell 2.

In Moonshell 2, navigate to the Skins folder and press A on Aero Ultimate.skn to apply the theme.