Skins for Edge Card

I've being trying to change the skins on my Edge card but most instructions require Win.rar, and I have a Mac (use RAR expander to put games on). I tried following the instructions but my skins only show up on Moonshell. Does anyone know what I am doing wrong or how to add skins using a Mac? Please help...

Find where the default skin files are on your MicroSD (if it exists). Overwrite the images etc.

Woo Hoo - I finally got it to work - thanks for the help:)