Start by copying over an existing skin.
Change the name of the skin folder from "copy of <oldname>" to "<newname>".
Go in to the folder and rename <oldname>.ini to <newname>.ini
Open <newname>.ini and go to the [Scripts] section.
Save it and go back to windows explorer.
Rename one of the old sub-skin folders (ie: "iGMap") to your new "<sub-skin-folder>". Each window/sub-window of a program can be embedded with its own set of skins, so there is a sub-folder under the main skin folder. You will just start out with embedding the main window so delete all other sub-directories of the skin.
Now go into your <sub-skin-folder> and rename the <old-folder>.ini (ie: "SKINbedder\iGuidance\iGMap\iGMap.ini")
to <sub-skin-folder>.ini. Then open it and change the name of the section at the top to match the filename to (ie: [iGMap] to [<sub-skin-folder>])
Next find the window title and class using auto it window tool.
Set any other things you want to mess with and save it.
Now rename one of the other ini files to <new-skin-name>.ini
Rename the [<section>].
Change the .png paths to your new skins images (one all-up, one all-down).
[<button-name>] has position, and OnPressUp/Down scripts.
Rinse & Repeat