Can I change the individual icons to my own icons?
Yes, you can modify whatever you like in the skins for your own use.
Most of the skins use font icons to make sure they look sharp on high resolution displays, so you're limited to the icons available in the particular font used in the skin. But if you know how to work with CSS, you can customize whatever you like, even changing the icon font if the current one doesn't suit your needs.
Please note that we're not able to provide technical support for the skins modified by third parties. We can only support the software that has been created and modified by our own developers.