Can I change the license of Joomla School Templates as I want?

I have created new Joomla Templates by using some Joomla School Templates. Currently it is licensed under a Creative Commons. So it provides the permission to the public to share and to use my work. But I do not want it to be like that for the modified Joomla School Templates by me.
I just want to know the ability of changing the license. Can I adapt another license after change the Joomla template?
