Put your phone on memory card mode, and then create a folder called skins, it should be made on your phone's memory (at least i prefer it there); once connected, you'll see two more drives, usually E: and F:, but the can be technically any letter (the last letter should be phone's memory).
Now search for a .system folder, if you can't find it, click on Tools (Herramientas) then folder options (Opciones de carpeta) view (Ver) and tick out this boxes: hide extension known file types, hide protected operating system files, show hidden files and folders, then click OK, and you should see the .system folder; if you don't see a folder like that try installing a Java (it should appeir once you flashed your phone).
Now create folder and name them: skin1, skin2, and keep like that 'til skin10 and inside each it should be all the files you have (.ini, .gif, .bmp, .ezx and the svg folder), please, always fill in order, skin1, then skin2 and like that in order.
Then once you have 1 or two or 10 skins inside your phone's memory, disconnect your phone, click on shortcuts then change theme and click on options create theme and then change sideways (click to the right) and scroll all the way down, til the see an option named skins: click on it, and choose your skin, once you choose it, click on save! and that's it, Once that's done you can change the wallpaper and plenty of things with the options there.
Original post:
How to install skins
