Configurate a theme

Hello everyone!!

I have a problem and I will tell you why.

I bought a theme, with HTML5 and CSS3, this: https://codecanyon.net/item/modern-music-streaming-app-template-hmtl-css-ionic-3-musicvic/25283146

I can create a new project in ionic, basic and I can modificate it. But I don´t know how can i do it with this theme. How can up this theme to Ionic platform and after that, how can modificate only HTML5 and CSS3.

One more thing, Is it possible, modificate the HTLM code and CSS3 code without Ionic platform, I don´t want compilate anything, only want chang some code.

Thanks