As there isn't an installer (you have a guide) you can easily remove everything. The dll file mods are included with Replacer, and a backup is made automaticlly. And most skins are application skins.
Transformation packs are mostly used by new Window users who can't customize their PCs manually. Do you think such users are capable of reverting the changes without the uninstaller?
You will end up with many broken PCs with this pack.
As this pack is mostly application based, you can unistall any done changes by just uninstalling the used application, or let the application stop working.