Go in the folder where your skin reside.
Change the extention of the UIS file to SSS
(the UIS is your main skin)
Change the extention of the SSS file corresponding to the subskin you want as the main one to UIS
(the SSS's are the various sub-skins)
Open the SSD file and reorder the entries, making your now primary apears in the [SkinStyle0] section. Once finished, save the SSD to it's original location.
(the SSD is the Sub-Skin Directory)
Alain